A  TECHNICAL  TREATISE 


ON 


SOAP  AND  CANDLES; 


WITH  A  GLANCE  AT 


THE  INDUSTRY  OF  FATS  AND  OILS. 


BY 

K.  S.  CRISTIANI,  Chemist, 

AUTHOR  OF  "PERFUMERY  AND  KINDRED  ARTS." 


ILLUSTRATED  BY  ONE  HUNDRED  AND  SEVENTY-SIX  ENGRAVINGS. 


PHILADELPHIA: 
HENRY  CAREY  BAIRD  &  CO., 

INDUSTRIAL  PUBLISHERS,  BOOKSELLERS  AND  IMPORTERS, 
810  WALNUT  STREET. 

LONDON: 

SAMPSON  LOW,  MARSTON,  SEARLE  &  RIVINGTON, 
CKOWN  BUILDINGS,  188  FLEET  STREET. 

1881. 


Copyright  by 
HENRY  CAREY  BAIRD  &  CO. 
1881. 


COLLINS,  PRINTER. 


rHEFACE. 


At  this  advanced  age  it  is  quite  unnecessary  to  speak  of 
the  irpportance  of  the  arts  of  manufacturing  soap  and  candles, 
as  they  have  become  necessary  to  all  civilized  nations,  and 
it  has  been  well  said  that  we  may  judge  of  the  degree  of 
civilization  of  a  people  by  knowing  the  amount  of  soap  they 
consume;  and  the  chemists  who  by  their  research  discovered 
the  methods  of  making  artificial  soda,  and  the  true  constit- 
uents of  the  fats  and  oils  and  their  utilization  may  be  con- 
sidered among  the  greatest  benefactors  of  their  race,  giving 
to  the  world  cheap  cleatiliness,  as  well  as  cheap  light. 

To  remove  these  arts  from  the  darkness  of  empirical  rules 
to  the  light  of  modern  science  is  one  of  the  principal  desires 
in  the  construction  of  this  work,  for  the  author  has  had  an 
experience  of  nearly  forty  years  in  these  and  kindred  arts, 
in  pharmacy,  chemistry,  soaps,  perfumery,  etc.,  and  he  well 
knows  how  little  science  has  been  consulted  in  making  these 
useful  articles,  and  how  much  guesswork  with  the  usual  un- 
certain results,  depending  upon  the  experience  which  the 
operator  may  have  had,  and  the  more  or  less  secret  his  pyo- 
cesses.  These  experiences  and  processes  may  have  served  a 
useful  purpose  when  the  arts  were  confined  to  making  domes- 
tic soaps  and  tallow  candles,  but  they  cannot  avail  at  the 
present  time,  when  they  have  become  a  thoroughly  scientific 
manufacture. 

To  render  this  work  as  complete  as  possible,  and  bring  all 
the  processes  and  formulas  up  to  the  present  time,  the  author 
has  given  much  time  and  care  to  its  compilation ;  aided  by 
his  long  experience,  and  having  access  to  all  that  has  been 
discovered  and  written  in  France,  Germany,  England,  and 
this  country,  he  issues  it  with  confidence  that  it  will  be  found 
a  useful  guide,  and  by  its  simplicity  and  correctness  well 
adapted  for  the  use  of  the  soap  and  candle  manufacturer  of 
the  present  age. 


iv 


PREFACE. 


Americans,  true  to  their  renown,  have  made  the  2;reatest 
advance  in  the  mechanical  part  of  these  arts  by  their  nume- 
rous improved  machines  and  apparatus  for  the  saving  of 
labor  and  improvement  in  the  products,  and  the  author  has 
illustrated  some  of  the  most  recent,  most  admirable,  and  most 
durable.  From  such  causes  they  are  making  rapid  strides 
towards  the  highest  excellence,  aided  by  these  improvements, 
so  that  our  products  will  compete  favorably  with  any  now 
made,  although  we  must  still  yield  to  France  the  palm  for 
superiority  in  toilet  soaps. 

In  the  department  of  candles  there  may  be  considered 
quite  a  revival  in  the  manufacture  at  this  time,  particularly 
for  the  better  class  of  goods,  and  he  has  therefore  given  it 
careful  consideration.  The  use  of  gas  in  the  large  cities  and 
petroleum  everywhere,  the  latter  particularly  affording  a 
good  and  cheap  light  for  the  million,  has  caused  this  manu- 
facture to  suffer  neglect  for  some  years;  yet  gas  has  its  disad- 
vantages and  petroleum  its  dangers,  so  that  candles  are  be- 
coming much  more  used  at  feasts  and  festivals  and  in  the 
homes  of  the  wealthy,  aiding  much  in  the  decorations  of 
modern  homes  by  their  attractive  designs  and  giving  a 
softer  and  more  pleasant  light. 

Knowing  the  importance  of  the  arts  of  w^hich  he  treats, 
the  author  has  sought  to  make  his  book  as  complete  as  possi- 
ble, and  he  believes  he  has  left  out  nothing  that  would  be 
useful  or  important.  How  well  he  has  performed  his  task 
experience  in  its  use  must  show. 

In  conclusion  the  author  takes  pleasure  in  acknowledging 
his  oblio^ations  to  the  writings  on  the  same  subject  of  Pro- 
fessors Morfit  and  Dussauce,  both  published  by  the  pub- 
lishers of  the  present  work,  and  of  those  of  Messrs.  Lich ten- 
berg,  Steinheil,  and  Malepeyre,  and  very  many  others  of  later 
dates,  indeed  too  many  to  enumerate  in  this  place. 

Philadelphia,  March  4,  1881. 

Note. — Owing  to  the  difference  that  obtains  in  the  several  countries  as 
to  the  weights  and  measures  and  thermometer  scales,  the  author  has  ren- 
dered all  the  French  or  decimal  weights  into  that  most  used  in  this  country 
— the  avoirdupois;  when  fluids  are  called  for,  into  that  of  the  apothecary, 
and  when  the  centigrade  scale  of  the  thermometer  is  given,  which  is  gene- 
rally the  case  in  most  scientific  books,  into  that  of  Fahrenheit,  thus  simplif)-- 
ing  the  subject  to  the  reader. 


CONTENTS. 


SECTION  I. 
Introduction. 

SECTION  II. 
History  of  the  Soap  and  Alkali  Trades. 

SECTION  III. 
Materials  used  in  the  Manufacture  of  Soaps. 


PAGE 

Alkalies  26 

Potash  27 

Comparative  Table  of  the  Quantities  of  Ashes  and  Potash  contained 

in  different  Vegetables   .       .       .       .       .       .       .       .  .30 

Quantity  of  Ashes  yielded  by  different  parts  of  Plants  ...  30 
Berthier's  Table  of  the  Quantities  per  cent,  of  Soluble  and  Insoluble 

Matters  31 

Table  of  the  Composition  of  the  Mixture  of  Soluble  Salts  extracted 

from  the  Ashes  of  some  Vegetables        .        .        .        .        .  .31 

Extraction  of  Potash  32 

Combustion  of  the  Plants  in  Furnaces        ...  .        .  33 

Leaching  or  Washing  of  the  Ashes    .......  34 

Red  American  Potash       .       .       .       .       .       .       .       .  .35 

Ashes  made  from  Tartar    .       .       .       .       .       .       .       .  .37 

Potash  made  from  Beet-root  Molasses        ......  38 

Composition  of  Commercial  Potashes  ;  Table  of  the  Composition  of 

the  Principal  Commercial  Potashes .       .       .       .       .       .  .39 

Purification  of  Potash       .........  40 

Soda  41 

Natural  Sodas  ;  Soda  of  Narbonne    .......  42 

Soda  of  Aigues-Mortes  ;  Soda  from  Sea- weeds  ;  Spanish  Sodas  .       .  43 
Mixed  Barilla ;  Salted  Barilla ;  Natron     .       .       .  •  .44 

History  of  the  Fabrication  of  Artificial  Soda     .....  45 

Fabrication  of  Crude  Soda  ;  Sulphate  of  Soda   .....  48 

Mixture  49 

Calcination       ...........  50 

Expense  of  Manufacturing  Artificial  Soda  in  France  ;  Production ; 

Artificial  Salted  Soda  52 


vi 


CONTENTS. 


PAGE 

Analysis  of  Crude  Artificial  Soda  ;  Refined  Carbonate  of  Soda  .       .  54 
Crystallized  Carbonate  of  Soda,  or  Crystals  of  Soda  ....  55 

Caustic  Salts  of  Soda        .        .        .        .        .        .        .       .  .57 

Analysis  of  an  English  Caustic  Soda  .......  58 

Table  of  Specific  Gravity  of  Sodas  and  amount  of  Caustic  Soda  .  , .  59 
Caustic  Soda  from  Cryolite;  Ammonia;  Rubinium  and  Caesium  .  60 
Lime        ............  61 

Water  64 

Table  of  Hardness  of  Waters  and  of  Soap  Decomposed  by        .  .66 

Salt  67 

Fats  and  Oils    ...........  68 

Fats  of  Animal  Origin ;  Tallows       .  .....  75 

Vohl's  Apparatus  for  Rendering  Tallow     ......  84 

Lard   86 

Rendering  by  Steam  ;  Wilson's  Process     ......  88 

Butter  90 

Composition  of  Butter       .        .        .        .        .        .        ,        .  .91 

Bone  Fat  92 

Horse  Fat ;  Glue  Fat  93 

Neat's  Foot  Oil ;  Kitchen  Fat  94 

Fish  Oils;  Cod  liver  Oil  95 

Oils  and  Fats  of  Vegetable  Origin     .......  97 

Physical  Properties  of  Oils;  Olive  Oil       .        .    '   .        .        •  .98 

Palm  Oil  99 

Palm-kernel  Oil  104 

Cocoa-nut  Oil    ...........  105 

Gallipoli  Oil      .       .  107 

Almond  Oil;  Sesame  Oil  .........  108 

Rapeseed  Oil  and  Coleseed  Oil ;  Groundnut  Oil         .       .        ...  109 

Ben  Oil  110 

Avocado  Oil ;  Sunflower  Oil  ;  Cotton-seed  Oil  .        .        .        .  .111 

Castor  Oil;  Poppy-seed  Oil  113 

Hempseed  Oil ;  Analyses  of  Hempseed  Oils      .       .       .       .  .114 

Nut  Oil ;  Beach-nut  Oil  115 

CamelineOil;  Mustard-seed  Oil ;  Colza  Oil  .  .  .  .  .116 
Hazel-nut  Oil;  Linseed  Oil;  Oleic  Acid,  Olein,  Commercial  Red  Oil  117 
Vegetable  Tallow ;  Shea  Butter  or  Galam  Butter  .  .  .  .121 
Butter  of  Nutmeg  or  Oil  of  Mace;  Composition  of  Butter  of  Nutmeg  .  122 
Tallow  of  Virola  ;  Oil  of  Laurel ;  Cocoa  Butter  .  .  .  .123 
Carapa  Oil ;  Malibar  Tallow ;  Goa  Butter  ;  Grape-seed  Oil ;  Oil  of 

Tobacco  Seeds;  Oil  of  Belladonna  Seeds      .....  124 

Waxes;  Beeswax;  Palm-tree  wax    •       .       .       .       .       .  .125 

Carnauba  Wax  ;  Myrtle  Wax  ;  Ocuba  Wax  ;  The  Wax  of  Bicuyda  ; 

Rosin  or  Colophony       .        .        .        .        .        .        .        .  .126 


CONTENTS. 


vii 


SECTION  IV. 

The  Recovery  op  Offal  and  other  Kefuse,  Fats,  and  Greases. 

PAGE 

The  Yield  of  Offal  Fats  hy  means  of  Sulphuret  {BIsnlphidel  of  Carbon  131 

Wool  Fat  and  Fuller's  Fat  132 

Composition  of  the  Residuum    .        .       .        .        .        .        .  .136 


SECTION  V. 

The  Adulteration  of  Fatty  Bodies. 

Olive  Oil ;  Oil  of  Sweet  Almonds     .       .       .       .       .       .  .140 

RapeseedOil;  Sesame  Oil  5  Linseed  Oil;  Black  Poppy  Oil;  Hemp- 
seed  Oil  141 

Castor  Oil;  Neat's  Foot  Oil;  Oleic  Acid;  Palm  Oil ;  Cocoa-nut  Oil  142 
Assays  of  Oils  ...........  143 

Qualitative  Assays    .       .       .       .       .       .       .       .       .  .144 

Table  of  the  Colorations  taken  by  different  Oils  .        .        .        .  .146 

Falsification  of  Lard ;  Alterations;  Falsifications       .        .        .  .148 

Falsifications  of  Tallows    .       .        .        .        .        .        .        .  .149 

Falsifications  of  Waxes  ;  Yellow  AVax  and  Sulphur ;  Yellow  Wax  and 
Yellow  Ochre;  Yellow  and  Whitf  Wax  and  Calcined  Bones;  Wax 

and  Resins  ;  Pitch,  etc  150 

Wax  and  Starch  or  other  Amylaceous  Substances  ;  Wax  and  T.dlow  .  151 

SECTION  VI. 
The  Chemical  Equivalents  Applicable  to  Soap. 

SECTION  VII. 
Saponification — Theoretical,  Chemical,  and  Practical. 


SECTION  VIII. 

,  Alkalimetry. 

Analysis  by  Measure,  or  Volumetric  Analysis  167 

The  Burette     ...........  168 

The  Pippette  172 

Flasks      .       .       .       .       .       .       .       .       .       .       .  .175 

Cylinders  for  Mixing .        .        .        .        .        .        .        .        .  .176 

Scales  and  AVeights  ;  Tincture  of  Litmus  ;  Cochineal  Tincture   .  .177 

The  Preparation  of  the  Tincture  of  Litmus  178 

Tincture  of  Cochineal ;  the  basis  of  Alkalimetry        .        .        .  .179 


Table  of  the  Quantities  of  Bases  Neutralized  by  Normal  Nitric  Acid  .  182 


viii  CONTENTS. 


PAGE 

Normal  Alkali  .  184 

Estimation  of  the  amount  of  Soda  in  Lyes  of  Potash  .  .  .  .185 
Analysis  of  Lime      .        .        .        .        .        .       .        .        .        .  194 


SECTION  IX. 
The  Application  of  Soaps. 

SECTION  X. 

The  Establishment  of  a  Soap  Factory  with  the  Necessary 

Plant. 

Description  of  the  Soap  Manufactory  for  Marseilles  Soap  of  Gontard 


in  St.  Quen,  near  Paris .       .       .       .       .  .       .  ,199 

Description  of  a  French  Soap  Factory  for  making  Mottled  Marseilles 

Soap ;  Factory  Building  203 

Kettles  ;  Fireplace  ;  Grate  ;  General  Chimney  .....  204 

Ash-pan  ;  Cisterns  in  Masonry  ;  Large  Masonry  Vats  ;  Cellars  ;  Basins  ; 
Frames ;  Store-rooms     .       .       .       .       .       .       .       .  .205 

Description  of  a  General  Plan  for  Manufactory  of  Soap  heated  by  Steam ; 
Boiler  ;  Fireplace ;  Chimney ;  Dome     ......  206 

Kettles  ;  Pipes  ;  Cisterns  ;  Cellars  ;  Foundation  of  the  Kettles  ;  Sheet- 
iron  Vats;  Frames        .       .       .       .       .       .  .  .207 

Drying-Room  208 

Kettles ;  Masonry  Kettles  211 

Cast-iron  Kettles  212 

Sheet- iron  Kettles  ;  Heating  of  Kettles  by  Fire  213 

Heating  of  Kettles  by  Steam     .       .       .       .       .       .       .  .215 

Steam  Series     .       .       .       .       .       .       .       .       .       .  .217 

Hubert's  Apparatus  for  Boiling  Soap  by  means  of  surcharged  Steam  .  219 

St.  John's  Steam  Jacket  221 

Morfit's  Steam  Jacket  222 

Caldrons  or  Boiling  Pans   .........  224 

Lye  Vats  225 

Siphon  ♦  •        .        .  .228 

Bogardus's  Eccentric  Mill  for  Grinding  ;  Drum  Sieve         .        .        .  229 

Soap  Frames  ;  Frames  of  Masonry  230 

Frames  of  Iron  231 

Whittaker's  Patent  Soap  Frames  232 

Frames  of  Wood  233 

Hersey's  Patent  Rotary  Soap  Pump  .       .       .       .       .       .  .236 

Cutting  Operation  238 

Slabbing  and  Barring  Machine  ........  239 

Caking  Machine  242 


CONTENTS.  ix 

PAGE 

Champion  Slabber;  Ralston's  Patent  Cutter,  with  Stamping  and 
Spreading  Attachments  ;  Crutching  Machines  ;  Steplien  Strunz's 
Soap  Crutching  Machine        ........  243 

Strunz's  Jacket  Crutching  Machine  245 

Minor  Implements     ..........  246 

SECTION  XI. 

The  Fabrication  of  Soaps. 
Soaps  by  Boiling       .........  248 

Tables  of  Lime  to  be  applied  in  proportion  to  contents  of  Potash  and 

Soda  to  pure  Carbonate  of  Alkali  .......  250 

Preparing  Potash  Lye  from  Wood  Ashes    ......  253 

JPreservation  of  the  Lyes   .        .       .        .        .        .        .        .  .254 

Tables  of  Experiments  with  Sodas  of  86°  and  72°  Baum6   .        .  .258 
Table  of  the  Contents  of  Anhydrous  Potash,  with  the  corresponding 

Specific  Gravities  and  degrees  of  Hydrometer  according  to  Baume  .  259 
Dalton's  Table  of  Potash,  contents  of  Lyes  according  to  their  Specific 
Gravities       ...........  259 

Table  of  the  Contents  of  Anhydrous  Soda,  with  the  corresponding 
Specific  Gravity  and  Hydrometric  degree  of  Baume  with  the  quanti- 
ties of  Fats  Saponified  by  Lyes  of  various  strengths        .        .  .261 
Dalton's  Table  of  the  various  specific  gravities  of  Sod:is  contained  in 

the  Lyes  262 

Hard  Soaps  (Soda  Soaps)  ;  to  make  a  good  Marble  or  Marseilles  Soap  266 

Clear  Boiling     .        .   269 

The  Grinding  or  Filling  of  the  Soap  .        .        .       .        .        .  .271 

The  Marbling  of  the  Soap  272 

Formulas  for  Marseilles  Soaps  ;  AVhite  Marseilles  (Castile  Soap)         .  274 

Pasting  276 

Separation;  Clear  boiling,  or  Coction        .        .        .        .        .  .277 

Fitting  279 

White  Soap  from  Olive  Oil  280 

White  Castile  (Marseilles)  Soap  as  made  in  England,  Germany,  and 
the  United  States  ;  Tallow  Soap  (Curd  Soap)        .        .        .  .281 

Palm  Soap   284 

Combinations  in  vogue  for  Palm  Soap  ;  Rosin  Soap  (Yellow  Soap)     .  285 
Rosin  Soap  with  Cocoa-nut  Oil  ........  286 

Resinous  Grain  Soap  and  Turpentine  Soap        .        .        .       .  .287 

Olein  Soap,  Oleic  Acid  Soap,  Elaidin  Soap  288 

First  and  second  services  of  Lye        .        .        .        .        .        .  .291 

Fitting  292 

Stirring  the  Soap  in  the  Frames        .......  294 

Castile  Soap  from  Cotton-seed  Oil  296 

Mottled  Castile  Soap  from  Cotton-seed  Oil  298 


X 


CONTENTS. 


SECTION  XII. 

The  Fabrication  of  Soaps  (continued). 
Extempore  and  other  Soaps. 

PAGE 

Little  Pan  Soaps  ;  Half-boiled  Soaps   301 

Tallow  Soap  by  the  Cold  Process  ;  Cocoa-nut  Oil  Soap  by  the  Cold 

Process   303 

Kosin  Soap  by  the  Cold  Process        .......  304 

Transparent  Rosin  Soap ;  Borax  Soap       ......  305 

Swiss  or  Half-boiled  Soaps  ;  Swiss  Palm  Soap    .....  306 

Swiss  White  Wax  Soap  ;  Swiss  Yellow  Soap   307 

Swiss  Rosin  Soap  ;  Swiss  Olein  Soap         ......  308 

Hard  Soap  from  Potash  Lye  ;  Tallow  curd  (grained)  Soap         .       .  309 

SECTION  XIII. 
The  Fabrication  of  Soaps  (continued). 
Soft  Soaps. 

Gentele's  Formula   .       .  .315 

Calculating  the  Proportion         .        .       .       .       .       .       .  .316 

Boiling  of  Soft  Soap  317 

Particular  Remarks   .        .        .        .        .        .        .        .        .  .318 

Grained  Soft  Soap  (Fig  Soap)  ;  Artificial  Grain  Soap        .       .  .320 

Elaidin  Soft  Soaps  321 

White  Soft  Soaps  322 

English  Crown  Soap  (First  Quality) ;  Crown  Soap  (Second  Quality)  ; 

Green  Soft  Soap   .  .323 

SECTION  XIV. 
The  Fabrication  of  Soaps  (concluded). 

SiLICATED  AND  OTHER  FiLLED  SOAPS. 

Common  Cocoa-nut  Oil  Soaps  ;  Common  Filled  Rosin  Soaps     .       .  326 

Soluble  Glass  Soap  (Silicated  Soap)  ;  Gossage's  Process  .  .  .  327 
Dunn's  Silicic  Soap  .       .       .       .       .       .       .       .       .  .331 

Guppy's  Process   332 

Davis's  Alkalumino  Silicic  Soap        .......  333 

Sand  Soap  ;  Quartz  Soap ;  Ponceln  Soap  ;  Greaves  or  Crackling  Soap  ; 

Bone  Soap   334 

Other  Filled  Soaps,  with  Fornuila;     .   335 


/ 


CONTENTS.  xi 

SECTION  XV. 
Nkw  Soaps  by  New  Methods. 

PAGE 

Saponification  of  Fats  by  means  of  Carbonated  Alkalies      .        .  .337 

Saponification  of  Fats  by  Sulphuretted  Alkalies  338 

The  Process  of  Mege  Mouries    ........  339 

Methods  of  M.  D'Arcet  341 

Soaps  by  Steam  Pressure ;  Bennett  &  Gibbs's  Apparatus    .        .       .  346 

^  SECTION  XVI. 

Soap  Analysis. 

Determination  of  the  amount  of  Alkali      ......  352 

Determination  of  Sebacic  Acids  and  of  the  Rosin       .       .        .  .357 

Congealing  Points  of  Sebacic  Acid  according  to  Stockhardt  .  .  358 
Bruckner's  Table  of  the  amount  of  Soap  and  Glycerine  furnished  by 

Fats  ;  Determination  of  the  amount  of  Rosin  .  .  .  .  .359 
Determination  of  Soap  as  to  Admixtures    ......  362 

Table  of  the  Analyses  of  Soaps  363 

Valuation  of  Soaps    ..........  364 

Cailletet's  Process;  Characteristics  of  the  Aqueous  Solutions  of  Soaps, 

Normal  Acid,  and  Alkaline  Liquor .        .        .        .        .        .        .  365 

Preparation  of  the  Normal  Acid  Liquor     ......  368 

Preparation  of  the  Normal  Alkaline  Liquor       .        .        .        .  .369 

Saponimetry  ;  Soaps  composed  of  Solid  and  Liquid  Fatty  Acids        .  370 
Soap  of  Oleic  Acid  and  Rosin   .        .       .        .        .        .        .  .375 

Mixtures  of  Potash  and  Soda     .       .       *.        .       .        .        .        .3  76 

SECTION  XVII. 
Remelting  of  Soaps. 
The  Whittaker  Remelter  381 

SECTION  XVIII. 
Miscellaneous  Useful  Soaps. 

Altenburge's  Rosin  Soap  ;  Dresden  Palm  Soap  ;  Oflf'enbach  Palm  Soap  383 

Wax  or  Bleaching  Soap ;  Bran  Soap  ;  Ox-gall  Soap  for  Scouring 
Woollens  ;  Scouring  Balls  384 

French  Scouring  Soap ;  Scouring  Tablets ;  Erasive  Soap ;  Labor- 
saving  Soap  ;  Country  Soap  ........  385 

Domestic  Soft  Soap  ;  Shaker's  Soft  Soap;  Borax  Soft  Soap;  Lubri- 
cating Soap    ...........  386 


xii 


CONTENTS. 


PAGE 

Agricultural  Soap  (Whale  Oil  Soap)  ;  Fig  Soap;  Pearl  Soap  Powder; 

Borax  Soap  Powder;  London  Soap  Powder  .  .  .  .  .387 
Belgian  Soft  Soap;  Ammoniated  Soap;  Medicated  Soft  Soap;  Marine 

Soap      ............  388 

SECTION  XIX. 
Toilet  Soaps. 

To  Render  and  Purify  the  Grease  390 

Toilet  Soaps  by  Boiling     .        .      • .        .        .        .        .        .        ,  392 

Half- Palm  Soap  393 

Pasting;  Separation;  Coction   ........  394 

Fitting ;  First  Liquefaction       .        .        .        .        .        .        .  .395 

Second  Liquefaction  .        .        .        .        .        .        .        .        .  .396 

White  Soap  from  Cocoa-nut  Oil  398 

SECTION  XX. 

Toilet  Soaps  by  the  Cold  Process. 

Extempore  Soaps. 

White  Soap  by  the  Cold  Process   402 

Rose  Soap        ...........  403 

Windsor  Soap  ;  Yellow  Soap  ;  White  Windsor  Soap  .        .        .        .  404 

Honey  Soap  ;  Glycerine  Soap  ;  Marsh-mallow  Soap  ....  405 

Old  Brown  Windsor  Soap  ;  Half-boiled  Soap — Swiss  Soaps       .        .  406 
Kurtin's  Table  showing  the  composition  and  product  of  Soap  by  the 
Cold  Process,  from  Concentrated  Lye  and  Mixture  of  Cocoa  Oil,  with 

Palm  Oil,  Lard,  and  Tallow   408 

SECTION  XXI. 

Miscellaneous  Toilet  and  Medicated  Soaps,  with  Fokmulas. 

Cold  Cream  Soap      ..........  409 

Bouquet  Soap;  Lemon  Soap     .        .        .        .        .        .        .        .  410 

Orange  Soap  ;  Elder- flower  Soap  ;  Heliotrope  Soap  ;  Frangipanni  Soap  41 1 
Superfine  Soaps  ;  Ambergris  Soap  (Ambrosial  Soap)  ;  Benzoin  Soap  412 
Jonquille  Soap  (Superfine)  ;  Millefleur  Soap  .  .  .  .  .413 
Savon  a  la  Marechale  (Surfin)  ;  Savon  Hygienique  (Extra  fine)  ;  Savon 

a  la  Violette  de  Parme   .        .        .        .        .        .        .        .       .  414 

Lettuce  Soap  ;  Cucumber  Soap  ;  Mousseline  Soap  ;  Savon  de  Muguet 

(Lilly  Soap)  ;  Rose-leaf  Soap  (extra  fine)  415 

Violet  Soap  (yellow)  ;  Vanilla  Soap  (superfine)  ;  Rose  Windsor  Soap  416 
Violet  Windsor  Soap  ;    Musk  Windsor  Soap ;    Names  for  French 

Toilet  Soaps  .417 


CONTENTS. 


xiii 


PAGE 

Medicated  Soaps ;  Carbplic  Soap ;  Medicated  Tar  Soaj) ;  SulpViur 
Soap  ;  Tooth  Soap        .........  418 

Tannin,  Salicylic,  Disinfectant,  Thymol,  Croton  Oil,  Benzoic  Acid, 
Castor  Oil,  Petroleum,  Paraffin,  Creasote,  Bromine,  Idonine,  Tur- 
pentine, Alum,  Borax  Toilet,  Mercurial,  Irish  Moss,  Bran,  Corn 
Meal,  Oat  Meal,  Camphor  Ice,  and  Wax  Soaps;  Eggj-yolk  Soap    .  419 

Bordhardt's   Herb    Soap;    Beef-marrow  Soap;    Spermaceti  Soap; 

Shaving  S^ps  in  Tablets       .        .        .        .        .        .        .  .420 

Shaving  Compounds ;  Floating  Soaps ;  Nymph  Floating  Soap ;  Rose 
Floating  Soap ;  Powdered  Soaps    .        .        .        .        .        .  .421 

Soap  Essences  ;  Transparent  Toilet  Soaps  ;  Transparent  Soap  by  the 
Cold  Process  ...........  422 

Transparent  Glycerine  Soap      ........  423 

Transparent  Soft  Soaps  ;  Liquid  Glycerine  Soap  ;  Soft  Toilet  Soaps  of 
Potash  ;  Shaving  Creams  ;  White  Soft  Soap  .....  424 

Almond  Shaving  Cream  ;  Rose  Shaving  Cream  ;  Ambrosial  Shaving 
Cream  ;  Shaving  Cream  by  Boiling  ;  Naples  Soap  or  Shaving  Cream  42G 

Soap  Balls  or  Savonettes;  Glycerine  Cocoa-nut  Oil  Soap    .        .       .  427 


SECTION  XXII. 

Manipulation  of  Soaps;  Machinery  and  Appliancks,  Pkrfuming, 
Coloring,  Finishing,  etc. 

Soap  Caking  Machine  428 

Cutting  Table ;  Hand  Press  431 

King's  Foot-power  Soap  Press  ;  Hersey's  Patent  Steam  Soap  Press  .  432 
Stripping  of  Soaps  ;  Rntschman's  Stripping  Machine        .        .       .  434 

Soap  Mills;  Rutschman's  Power  Soap  Mill  435 

Plotting  437 

Rutschman's  Vertical  Plotting  Machine  ;  Hydraulic  Plotting  JNIachine  ; 

Finishing  and  Polishing  Soap  Cakes  438 

Coloring  Toilet  Soaps        .        .        .       .        .       .       .        .  .439 

Perfuming  of  Toilet  Soaps  ;  Perfumes  for  Honey  Soap  .  .  .  440 
Perfumes  for  Glycerine  Soaps;  Perfumes  for  White  Windsor  Soap; 

Perfumes  for  Rose  Soaps       .        .        .        .        .        .        .  .441 


Perfumes  for  Elder-flower  Soap  ;  Perfume  for  Cashmere  Soap    .  .442 


SECTION  XXIII. 

Volatile  (Essential)  Oils,  and  some  other  Materials  used  for 
THE  Perfuming  of  Soaps. 

Oil  of  Valerian  ;  Oil  of  Bergamot     .......  443 

Oil  of  Bitter  Almonds      .........  444 


xiv 


CONTENTS. 


PAGE 

Oil  of  Lemon  ;  Oil  of  Fennel  ;  Gaultheria  or  Wintergreen  Oil  .  .  446 
Geranium  Oil ;  Caraway-seed  Oil ;  Oil  of  Jasmin       ....  447 

Limette  Oil ;  Oil  of  Lavender  ;  Oil  of  Cloves  448 

Neroli  or  Orange-tlower  Oil ;  Oil  of  Patchouly  ;  Oil  of  Portugal ;  Attar 

of  Roses,  Oil  of  Roses  449 

Oil  of  Sassafras  ;  Oil  of  Marjoram  ;  Oil  of  Thyme     ....  451 

Oil  of  Vitivert ;  Cassia  Oil;  Oil  of  Rosemary  ;  Oil  of  Canada  Snake- 
root;  Oil  of  Pimento  ;  Oil  of  Nutmegs  ;  Oil  of  Cinnamon       .        .  452 
Ambergris  ;  Musk  or  Bisam       ........  453 

Peruvian  Balsam  ;  Civet ;  Tincture  of  Civet      .....  454 

Tincture  of  Ambergris  ;  Tincture  of  Musk  .        .        .        .        .  .455 


PAET  II. 

MANUFACTURE  OF  CANDLES. 
SECTION  I. 

LXTRODUCTION,  INCLUDING  THE  ThEORY  OF  FlAME. 

SECTION  II. 

The  Materials  for  Candles,  with  their  Preparation. 

Preparation  of  Tallow  ;  Chopping  Board   ......  463 

Power  Machine  for  Cutting  Tallow;  Kettles  for  Rendering  in  small 


Factories  464 

Hood  for  Kettle  465 

Presses      ............  466 

Centrifugal  Mill  470 

Saponification  by  Lime      .        .        .        .        .        .        .        .  .472 

Wood  Frame- work    .        .        .        .        .        .        .        .        .  .474 

Hydraulic  Press        .        .        .        .        .        .        .        .        .  .475 

De  Milly's  Process  477 

Saponification  by  Sulphuric  Acid       .        .        .        .        .        .  .478 

Saponification  by  Sulphuric  Acid  without  Distillation  ;  Saponification 

of  Fats  by  Water  combined  with  Distillation  .  .  .  .  .479 
Saponification  by  Water  under  High  Pressure;  Prof.  Kraft's  Report 

on  Sebacic  or  Fatty  Acids      ........  480 

Distilling  Apparatus  .        .        .        .        .        .        .        .        .  .481 


CONTENTS-  XV 

SECTION  III. 
Materials  for  Candles  (continued). 

PAGE 

Paraffine   482 

Spermaceti        ...........  483 

Machine  for  Reducin^Crytallized  Cakes  to  Shreds  ;  Wax  .        .        .  484 

Sebacylic  Acid  ;  Elaidic  Acid ;  Glycerine  ......  486 

SECTION  IV. 
The  Manufacture  of  Candles. 
Wicks,  AND  their  Preparation. 

Wick  Cutters  490 

Apparatus  to  combine  the  Soaking  of  the  AVicks  with  the  Cutting       .  492 

SECTION  Y. 
The  Manufacture  of  Candles  (continued). 
Dipped  Candles. 

The  Necessary  Apparatus  ......        ...  494 

SECTION  VI. 

The  Manufacture  of  Candles  (continued). 

Moulded  Candles. 

The  Moulds  502 

Moulding  by  Hand  503 

Moulding  by  Machinery     .........  504 

Leubel's  Moulding  Machine       ........  506 

Morgan's  Moulding  Machine  508 

Improved  Continuous  Wick  Machine  .       .        .        .        .        .  .512 

Ashley's  Moulding  Machine ;  Camp's  Moulding  AVhecl      .       .        .  513 
Stearine  Candles       .        .       .       .        .        .        .        .       .  .515 

Moulding  Stearic  Acid  Candles  .       .        .        .        .        .        .  .517 

The  Moulds  for  Stearic  Acid  Candles;  Bleaching  the  Stearic  Acid; 
Moulding  Stearic  Acid  Candles  by  Hand        .       .        .        .  .518 

Moulding  by  Steam  520 

Paraffine  Candles  ;  Moulding  Paraffine  Candles  .....  522 
Spermaceti  Candles  ;  Moulding  Spermaceti  Candles  .        .        .  .523 

Wax  Candles  524 

Moulding  Wax  Candles     ......  .        .  525 

Large  Bougies  or  Cierges  for  Churches       ......  526 


XVI 


CONTENTS 


SECTION  VII. 

The  Manufacture  of  Candles  (continued). 
Polishing  and  Finishing. 

PAGE 

Apparatus  for  Polishing  and  Finishing       ......  528 

SECTION  VIII. 

The  Manufacture  of  Candles  (continued). 

Composite  and  Patent  Candles. 

Belmont  Sperm  Candles;   Belmont  Wax  Candles;    Star  Candles; 

Cerophane  Bougies  ;  AdamanVme  Candles;  Artificial  Wax  Candles  532 
Diaphanous  Candles  ;  Composition  Candles  ;  Various  Patent  Candles  533 

SECTION  IX. 

The  Manufacture  of  Candles  (concluded). 

Decorated  and  Colored  Candles,  Tapers,  Night  Lights,  etc. 

Colored  Candles   .537 

Toy  Candles,  Decorated  Candles       .......  538 

Wax  Tapers  540 

Night  Lights  or  Tapers     .       .       .       .       ,       .       .       .  .542 


APPENDIX. 


The  Metric  System  of  Weights  and  Measures. 

Weights  and  Measures       .        .        .        .        .        .        .        .  .545 

Tables  showing  the  Relative  Value  of  English  and  French  Measures  .  547 
Hydrometers  and  Thermometers       .        .        .        .        .        .  .555 

Thermometers  .        .        .        .        .        .        .        .        .        .  .557 

Centigrade  and  Fahrenheit        ........  558 

Note. — Soda  Ash  by  the  Ammoniacal  Soda  Process         .       .  .561 

Index  563 


A  TECHNICAL  TREATISE 

ON 

SOAP  AND  CANDLES, 

WITH  A  GLANCE  AT  THE 

INDUSTRY  OF  FATS  AND  OILS. 


SECTION  I. 

INTRODUCTION. 

The  term  soap  is  now  applied  to  all  those  compounds  of 
oils  or  greases  or  sebacic  acids  with  the  salifiable  bases  or 
alkalies,  which  by  their  detergent  properties  aid  in  the  re- 
moval of  dirt  or  grease  in  washing,  scouring,  and  scrubbing. 
The  term  detergent  means  the  power  of  rendering  soluble  in 
water  the  adhering  grease  or  dirt  on  the  skin  or  clothes  ;  for 
which  purpose  soap  is  now  universal Ij^  applied  by  all  nations. 
Indeed  we  can  almost  form  a  true  estimate  of  the  degree 
of  civilization  to  which  a  country  has  attained,  by  knowing 
the  amount  of  soap  used  by  its  inhabitants. 

It  is  perhaps  unnecessary  here  to  mention  the  great  im- 
portance and  usefulness  of  the  art  of  manufacturing  soap,  as 
an  article  so  universally  used  has  attracted  the  attention  of 
chemists  from  the  most  remote  period  ;  yet,  although  soap 
has  been  made  and  used  for  so  long  a  time,  it  is  only  in 
modern  times  that  its  manufacture  has  reached  a  scientific 
character,  for  it  is  less  than  sixty  years  since  'Chevreul  first 
advanced  the  proper  theory  of  saponification,  and  made 
known  the  elements  of  the  fats  and  oils  and  their  chemical 
reactions  with  the  bases  or  alkalies. 
2 


18 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


To  the  magnitude  of  its  agriculture,  manufactures,  and 
commerce  we  turn  to  discover  the  wealth  of  a  nation,  and  in 
applying  the  light  of  science  to  all  of  the  most  important 
manufactures,  and  thereby  improving  the  quality  and  cheap- 
ening the  cost,  we  increase  the  demand,  give  importance  and 
character  to  an  art,  enlarge  and  extend  the  product,  and  bring 
w^ealth  to  a  country  and  its  people. 

While  as  Americans  we  are  proud  to  know  that  we  excel 
in  the  many  new  machines  and  apparatus  intended  to  facili- 
tate the  manufacture  of  soaps,  and  are  constantly  improving 
the  quality  of  our  products,  yet  we  still  procure  from  Europe 
many  of  their  superior  productions ;  but  as  we  realize  that 
there  is  still  something  to  learn,  and  we  seek  to  excel,  we 
are  quite  likely  ere  long  to  equal  any  soaps  made  in  any 
country. 

The  arts  of  manufacturing  soaps  and  candles  rest  upon  ex- 
act principles  and  fixed  rules, and  are  true  chemical  industries. 
So  it  is  important  that  the  manufacturer  should  endeavor  by 
steady  experiment  and  practice  to  learn  these  arts  scientifi- 
cally, that  he  may  fully  understand  their  true  foundations. 

Being  chemical  arts,  it  has  been  necessary  to  use  many 
scientific  terms,  but  the  author  has  sought  to  give  the  sim- 
plest explanations  while  yet  retaining  accuracy,  that  the 
worker,  who  may  be  without  experience,  may  fully  under- 
stand the  meaning  of  all  he  reads,  and  it  is  his  object  here  to 
make  all  processes  as  simple  as  possible,  compatible  with 
their  accuracy  and  importance. 

In  conclusion,  he  desires  to  give  a  word  of  advice  founded 
on  experience,  to  all  who  wish  to  enter  into  the  important 
manufacture  of  soaps,  as  well  as  to  those  already  in  it ;  to 
seek  the  most  approved  means  of  making  good  honest  soaps, 
soaps  that  will  bear  all  tests,  and  bring  him  reputation, 
respectability,  and  fortune,  for  though  by  sophistication  and 
adulteration  a  larger  quantity  may  be  marketed  by  the  at- 
traction of  low  prices,  yet  quality  is  the  only  true  test,  and 
superiority  should  be  the  aim,  as  it  is  the  only  road  to 
respectability  in  the  trade.  • 


HISTORY  OF  THE  SOAP  AKD  ALKALI  TRADES. 


19 


SECTION  II. 
HISTORY  OF  THE  SOAP  AND  ALKALI  TRADES. 

If  we  could  go  back  sufficiently  far  in  the  history  of 
nations,  we  should  find  that  commerce  meant  the  barter  of 
the  commonest  natural  products.  Just  as  people  progressed 
in  civilization  so  did  their  wants  increase,  and  to  meet  their 
requirements  it  became  necessary  to  apply  to  natural  pro- 
ducts much  study,  to  shape  them  to  suit  the  desired  uses. 
So  we  see  the  beginning  of  manufactures  which  now  repre- 
sent the  most  important  factor  in  the  commerce  of  nations. 
While  in  early  times  everything  was  accomplished  through 
agriculture  and  the  increase  of  the  earth,  it  is  still  the  most 
important,  but  guided  by  the  intervention  of  science. 

In  considering  the  history  of  manufactures,  we  will  see 
that  they  have  been  chiefly  developed  through  chemical  re- 
search, and  few,  if  any,  have  been  more  interesting  or  im- 
portant to  the  progress  of  a  country  than  the  branches  known 
as  the  soap  and  alkali  manufactures  and  trade.  So  we  must 
consider  chemistrj^  as  a  science  built  on  a  framework  which 
has  been  raised  by  the  labors  of  such  men  as  Berzelius,  La- 
voisier, Scheele,  Gay-Lussac,  Leleivre,  and  others,  and  see  the 
application  of  derived  knowledge  to  the  arts  and  manufac- 
tures, and  appreciate  the  natural  consequences  of  cheap  soap 
and  cheap  oils,  ''cheap  cleanliness  and  cheap  light." 

While  we  find  that  soap  has  been  used  for  some  centuries 
and  by  many  nations,  it  is  not  so  well  established  that  tlie 
ancients  were  acquainted  with  it,  as  it  is  known  that  they 
used  ashes  and  alkaline  earths;  which,  though  they  had  a 
detersive  power,  yet  as  found  in  nature  were  very  corrosive 
and  destructive  to  fibrous  material  and  to  the  human  skin. 
These  natural  substances  are  still  used  in  some  countries  as 
substitutes  for  soap. 


20  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


It  is  difficult  correctly  to  ascertain  at  what  time  or  by 
what  nation  soap  was  first  made  and  used..  It  is  claimed  hy 
some  that  the  Greeks  first  invented  it,  yet  it  is  first  distinctly 
spoken  of  as  an  invention  of  the  Gauls,  whence  the  Germans 
obtained  the  art  and  were  distinguished  for  their  superior 
goods,  whicli  was  at  least  a  century  before  Italy  established 
its  manufacture  in  the  eighth  century,  and  in  the  beginning 
of  tbe  tenth  century  it  was  introduced  into  France,  where 
large  factories  were  established  in  Marseilles  hy  a  colony  of 
Phoceans,  decendants  of  the  Greeks.  Marseilles  was  particu- 
larly adapted  to  this  industry,  as  all  the  needed  materials 
were  there  abundant.  Olive  oil  w^as  common,  and  the  neigh- 
boring sea-coast  provided  the  vegetable  sodas,  and  the  sea- 
port on  the  Mediterranean  had  a  large  commerce  with  all 
Europe  and  the  Levant.  So  France  became  the  great  market 
for  this  useful  product,  and  was  celebrated  for  the  superior 
quality  of  its  soaps,  and  very  deservedly,  as  the  processes 
then  in  use  have  been  fixithfully  adhered  to,  and  all  these 
combinations  are  to  this  day  wisely  continued  with  the  ad- 
dition of  improved  applications  natural  to  the  adv^ance  in 
everything  else.  These  manufacturers  have  with  prudence 
added  to  their  materials  onl}^  such  as  have  proved  after 
careful  experiment  to  be  of  decided  advantage. 

In  tlie  war  with  Spain  in  the  beginning  of  this  century 
the  sources  of  much  of  their  material  both  alkali  and  oil 
were  cut  oft',  very  much  to  their  disadvantage,  and  the 
government  with  great  wisdom  ottered  a  large  reward  for 
the  discovery  of  the  means  of  substitution.  This  was  ac- 
complislied  by  Leblanc  w^ho  discovered  a  process  for  making 
caustic  soda  from  culinary  salt;  a  discovery  that  has  been  of 
great  importance,  and  may  be  said  to  have  revolutionized  the 
soap  and  alkali  trades;  for  artificial  soda  as  it  is  called  is 
now  universally  used.  So  with  their  olive  oil  which  became 
scarce  and  dear,  for  it  was  also  largely  supplied  by  Spain  ; 
the  manufacturers  Avere  compelled  to  try  other  oils,  and 
poppy  oil,  hempseed  oil,  sesame  oil,  and  groundnut  oil,  were 
used  in  combination.  The  latter  oil  especially  proved  a  suc- 
cess, in  fact  an  improvement  to  the  soa[».    So  at  the  present 


HISTORY  OF  THE  SOAP  AND  ALKALI  TRADES. 


21 


time  no  Marseilles  (Castile)  soap  is  made  with  olive  oil  alone, 
as  the  addition  of  any  of  these  oils  in  certain  proportions  has 
been  proven  beneficial ;  pi-eventing  the  soap  from  acquiring 
too  solid  a  consistency  when  dry,  which  that  made  from  olive 
oil  alone  was  sure  to  have,  except  when  made  with  lye  from 
barilla,  which  contains  a  large  percentage  of  potash,  and  the 
hygroscopic  character  of  this  alkali  had  a  like  effect  in 
keeping  the  soap  plastic  and  more  soluble. 

In  turning  from  France  to  England  we  see  that  but  little 
progress  was  made  in  this  art;  soap  was  indeed  made,  but 
only  in  the  crudest  form  and  gener.illy  in  the  household  or 
for  fulling.  The  first  mention  of  its  manufacture  was  in 
1524,  in  London;  in  1641  a  factory  for  its  production  is  de- 
scribed in  some  records  in  the  British  Museum.  The  trade 
was  retarded,  like  many  others,  by  the  special  privileges 
granted  to  a  subject  by  the  sovereign,  and  again  by  the  heavy 
excise  duties.  These  obstructions  prevented  progress  so  that 
but  little  improvement  can  be  found  from  the  time  of  Queen 
Anne  till  the  present  century,  when  in  1804  Muspratt  made 
artificial  soda  by  Leblanc's  process,  which  immensely  cheap- 
ened and  increased  the  manufacture  of  the  article.  Yet  to 
the  date  of  the  first  International  Exhibition  of  1851,  England 
had  made  so  little  progress  that  she  was  surprised  that  the 
manufacturers  of  other  countries  carried  off  nearly  all  the 
prizes  given  for  that  branch.  This  surprise  caused  an  agita- 
tion for  the  repeal  of  the  excise,  which  was  finally  accom- 
plished in  1853.  The  result  of  this  repeal  was  so  beneficial 
that  we  find  in  1870  the  amount  manufactured  had  increased 
fully  fifty  per  cent. 

Yet  England  has  not  kept  pace  with  some  other  countries 
in  the  progress  of  the  art,  though  some  important  discoveries 
in  cheapening  the  cost  of  soap  have  there  been  made,  par- 
ticularly the  addition  of  rosin,  palm  oil,  and  silicate  of  soda. 
The  former  article  may  be  considered  an  ameliorater,  making 
it  more  soluble ;  the  latter  while  cheapening  does  not  mate- 
rially injure  its  quality,  the  silicate  of  soda,  having  an  alkaline 
reaction  and  a  detersive  quality,  being  less  objectionable  than 


22 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


the  many  articles  now  in  use  as  sophistications  of  soap,  some 
of  which  are  pernicious  and  should  be  abandoned. 

In  1870  England  manufactured  about  250,000,000  pounds 
of  hard  and  soft  soap,  but  since  then  we  cannot  trace  any 
material  increase,  for  countries  that  then  w^ere  principally 
dependent  for  soaps  on  England  now  make  most  of  their 
own.  But  of  alkali  England  has  steadily  increased  its  sup- 
ply until  it  now  in  quantity  excels  all  other  nations. 

The  Germans,  who  in  early  times  made  the  best  soap  and 
exported  it  to  other  countries,  have  made  but  moderate 
progress  in  modern  times.  At  the  present  day,  however,  the 
practice  of  the  art  being  open  to  all  the  people,  who  have 
established  many  small  factories  and  applied  to  the  trade  its 
true  chemical  character,  they  are  producing  superior  goods, 
though  this  superiority  is  not  sufficiently  maintained  to 
claim  particular  notice  in  comparison  with  the  products  of 
other  countries.  The  soft  soap  of  Germany  is  still  much 
used  for  household  purposes  as  well  as  for  manufacturing,  and 
it  has  acquired  a  reputation  for  excelling  in  quality  that  of 
other  countries.  Why,  we  cannot  say,  for  there  have  been 
neither  many  improvements  nor  much  science  given  to  its 
manufacture. 

Of  the  manufacture  of  alkali  in  Germany  there  had  been 
but  a  limited  improvement  for  many  years,  until  it  was  found 
that  England  was  extending  her  alkali  trade  to  an  enormous 
extent,  when  the  Germans  saw  the  necessity  of  improving 
their  goods  and  economizing  their  processes,  which  latter 
had  heretofore  been  conducted  in  a  very  wasteful  manner. 
This  compelled  them  to  establish  large  works  and  to  employ 
experts  at  liberal  wages.  The  result  has  been  not  only  a 
better  product,  but  a  large  increase  in  the  quantity  manufac- 
tured and  in  a  single  decade. 

Eor  a  period  of  time  past  recollection  Germany  had  made 
both  soft  and  hard  soaps  with  potash  lyes,  the  latter  by  using 
salt  in  turning  the  soft  soap  into  hard,  the  culinary  salt  or 
chloride  of  soda  producing  a  decomposition  by  parting  with 
its  chlorine,  forming  chloride  of  potash,  which  w^as  precipi- 
tated in  the  spent  lye  along  with  the  glycerine,  leaving  a 


HISTORY  OF  THE  SOAP  AND  ALKALI  TRADES. 


23 


sebacic  acid  soda  soap.  This  process  is  still  in  vogue  in 
countries  where  wood  is  bujnt  as  fuel,  and  potash  and  wood  " 
ashes  are  abundant ;  notably  Russia  and  the  newly  settled 
portions  of  the  United  States.  Germany  now  employs  the 
artificial  soda  in  almost  all  its  soaps,  and  is  making  much 
of  its  alkali  from  cryolite  for  the  use  of  the  glass  manufac- 
turers as  well  as  the  soap  boilers. 

In  our  own  country  there  has  been  a  steady  progress  in 
the  improvements  constantly  making  in  this  useful  and 
important  art,  until  now  we  are  producing  goods  which  for 
quality  compare  favorably  with  any  made  elsewhere ;  more- 
over we  have  invented  much  new  and  improved  machinery 
and  apparatus  that  greatly  facilitate  the  processes,  saving 
labor  and  time  and  improving  the  quality.  Thus  the  United 
States  is  at  this  time  but  little  behind  any  other  country, 
either  in  the  amount  made  or  in  the  quality  of  the  article ; 
while  in  the  economy  and  facility  of  their  manufacture 
this  industry  is  in  advance  of  that  of  nearly  all  other  coun- 
tries, and  is  steadily  progressing,  so  that  it  cannot  be  long 
before  we  shall  equal  in  quality  and  excel  in  quantity,  for 
already  we  are  making  soap  in  larger  quantities  than  Great 
Britain,  and  are  but  little  behind  France.  We  are  also 
making  so  much  of  our  own  alkali  that  we  shall  soon  be  inde- 
pendent of  other  countries.  We  have  hitherto  been  supplied 
from  England,  which  is  still  largely  in  advance  in  the  pro- 
duction of  soda  and  its  adjuncts,  having  in  operation  over 
fifty  large  alkali  works  and  making  goods  valued  at 
$20,000,000  per  annum.  At  the  present  time  the  United 
States  has  several  of  these  works  and  many  more  are  pro- 
jected. 

When  Chevreul  described  the  exact  constituents  of  the 
fatty  bodies,  and  made  known  the  processes  for  their  separa- 
tion, a  great  impetus  was  given  to  both  the  arts  of  soap  and 
candle  manufacture.  The  stearine  or  solid  part  was  made 
into  candles  while  the  olein  or  liquid  part  was  converted 
into  soap,  the  glycerine  which  had  previously  been  thrown 
away  was  extracted  from  the  sublye  and  utilized  and  has 
since  become  of  great  importance  in  many  arts. 


24 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


The  importation  of  palm  and  cocoa-nut  oils  added  an  im- 
portant variety  to  the  list  of  soaps,  particularly  of  toilet- 
soaps,  the  former  being  a  useful  and  pleasant  material,  im- 
})roving  all  soaps  into  which  it  enters,  which  cannot,  hc^wever, 
be  said  of  cocoa-nut  oil,  as  it  retains  a  rancid  odor  wdiich  it 
seems  impossible  to  remove,  and  wdiich  is  to  most  people 
objectionable,  so  that  it  should  be  used  with  caution.  On 
the  other  hand,  it  has  many  good  qualities,  making  soap 
handsome  in  appearance  and  in  use  giving  a  copious  lather. 
It  has  also  properties  peculiar  to  itself;  thus  it  saponifies  only 
in  strong  lyes,  and  will  dissolve  in  salt  water  and  is  often 
called  marine  soap.  It  will  also  retain  a  large  percentage  of 
water  without  impairing  its  solidity  or  appearance.  These 
properties  it  in  some  degree  imparts  to  other  soaps  to  which 
it  may  be  added,  and  it  has  been  the  means  of  much  sophis- 
tication and  adulteration,  which  has  given  to  purchasers  an 
idea  of  inferior  quality,  yet  to  some  it  is  a  favorite  because  of 
the  richness  of  its  lather. 

In  giving  statistics  of  soaps,  w^e  can  only  give  approxi- 
mate figures,  as  we  find  nothing  later  than  1870  and  1876. 
Great  Britain  has  over  350  soap  manufactories  making  over 
250  million  pounds  of  soap  per  annum,  of  which  50  million 
w^ere  exported.  France  has  fewer  factories  but  makes  quite 
as  much,  including  toilet-soaps,  while  the  value  is  much 
greater.  Of  Germany,  we  have  only  Berlin,  which  makes 
about  30  million  pounds  per  annum.  The  United  States  m 
1870  made  nearly  200  million  pounds,  while  at  this  date  the 
increase,  judging  from  our  own  researches,  must  be  fully 
thirty  per  cent.,  as  that  has  been  nearly  the  amount  of  in- 
crease of  export.  We  ship  much  to  South  America  and 
elsewhere. 

Thus  in  reviewing  the  history  of  the  soap  and  alkali  trades 
we  see  that  neither  has  attracted  much  attention  till  modern 
times,  for  even  looking  back  so  short  a  period  as  fifty  years 
we  find  that  they  received  but  little  notice,  except  in  France, 
where  at  that  time  in  Marseilles  alone  there  were  made  about 
120  million  pounds  per  annum.  About  this  period  Paris 
founded  soap  establishments  similar  to  those  in  Southern 


HISTORY  OF  THE  SOAP  AND  ALKALI  TRADES. 


25 


France,  and  made  goods  that  rivalled  those  of  the  older 
manufacturers,  hesides  numerous  and  superior  toilet-soaps  as 
well  as  family  and  industrial  soaps.  The  former  were  better 
than  the  world  had  ever  known;  and  this  superiority  has  been 
maintained  against  all  competition. 

So  we  reach  our  own  times  and  find  large  soap,  candle, 
and  alkali  works  in  nearly  all  countries,  whose  products  are 
consumed  in  vast  quantities,  and  are  a  staple  of  commerce  of 
the  first  importance,  requiring  large  capital,  employing  many 
hands,  and  giving  wealth  to  the  nations.  Although  many  of 
these  productions  are  still  of  inferior  quality,  the  arts  are  of 
the  most  progressive  character,  and  there  is  a  steady  improve- 
ment accompanied  by  a  constant  effort  towards  superiority — 
healthy  elements  which  ere  long  must  lead  almost  to  perfec- 
tion. 

We  must  now  leave  this  fascinating  subject  with  a  notice 
of  some  natural  products  that  are  used  as  substitutes  for 
soap,  though  they  have  not  yet  been  found  of  importance 
enough  to  supplant  it  in  utility — such  as  the  berries  of 
the  soap-tree  {Sapindus  saponaria)  of  South  America  and 
the  West  Indies;  aquilla  bark  {Qiiillaza  saponaria)  used  for 
washing  silk  and  woollens;  the  juice  of  the  soapwort  {Sap- 
onaria officinalis)  or  "bouncing-bet,"  all  of  which  form  a 
lather  with  water.  In  California  the  Phalangium  pomari- 
dianum  is  used  as  a  substitute  for  soap  and  has  its  odor; 
there  are  also  many  natural  earths  and  clays  that  have  an 
alkaline  reaction  and  can  be  used  as  substitutes  for  soaps, 
though  with  caution  as  they  usually  contain  other  chemicals 
which  might  prove  injurious  to  the  skin  or  clothes.  Many 
of  these  natural  products  have  been  utilized  in  pharmacy  and 
the  arts. 


26 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


SECTIOIT  III. 

MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS. 

ALKALIES. 

Besides  the  two  indispensable  ingredients  that  constitute 
the  materials  of  which  all  soap  is  made,  viz.,  alkali  and  fats 
or  oils,  there  are  several  others  scarcely  less  important  in  the 
art,  as  lime,  salt,  water,  etc.,  all  of  which  wnll  be  properly 
described. 

The  two  important  alkalies  potash  and  soda,  which  are  the 
oxides  of  the  metallic  bases  potassium  and  sodium,  in  the 
new  chemical  nomenclature  are  termed  potassium  hydrate 
and  sodium  hydrate,  meaning  the  caustic  alkalies  in  solu- 
tion, and  are  described  by  the  formulae  iTaHO  caustic  soda, 
KHO  caustic  potash.  From  these  oxides  the  bases  can  be 
formed,  which  have  for  the  chemist  many  peculiar  and  inter- 
esting properties,  but  for  the  soap  maker  are  of  but  little 
interest,  having  no  practical  use  in  his  art.  But  as  regards 
the  oxides  or  what  we  call  potash  and  soda,  he  cannot  be  too 
intimately  acquainted  with  all  their  properties,  in  fact  an 
accurate  knowledge  of  them  is  necessary  to  facilitate  his 
manufactures,  for  by  this  means  he  can  intelligently  account 
for  all  success  as  well  as  all  mistakes  that  may  occur  in  his 
processes. 

While  each  of  the  alkalies  mentioned  will  form  soaps, 
the  soaps  so  formed  will  have  different  characters,  though 
each  may  have  equal  detergent  power  in  dissolving  grease 
and  dirt,  yet  they  have  different  uses  in  the  arts  and  for 
domestic  purposes,  and  are  quite  different  in  their  physical 
properties,  the  soaps  from  potash  being  soft,  those  from  soda 
hard.  This  property  is  often  utilized  to  modify  the  quality 
of  soaps,  to  make  one  harder  or  the  other  softer. 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  27 


The  other  ingredients  of  soap,  namely  the  fatty  acids,  have 
many  and  distinct  properties,  the  study  of  which  is  scarcely 
less  important  than  that  of  the  bases  or  alkalies,  for  as  a 
fatty  or  sebacic  acid  may  be  more  or  less  solid,  so  will  it 
impart  this  jDroperty  to  the  soaps  into  which  it  enters; 
thus  stearine  or  the  hard  principle  of  fats  will  form  a  much 
more  solid  soap  than  oleine  or  the  liquid  part.  This  rule 
may  have  some  exceptions  under  certain  conditions. 

In  the  working  of  these  fatty  acids,  or  their  behavior  when 
combined  with  the  alkaline  bases,  they  may  each  have  some 
peculiarity  either  in  saponification  or  in  the  resulting  soap, 
so  we  see  the  importance  of  a  close  studj^  of  the  character- 
istics of  each.  For  those  in  common  use  we  can  take  for  our 
guide  the  experience  of  others,  but  there  are  constantly 
arising  new  oils,  greases,  waxes,  etc  ,  witli  whose  properties 
we  must  experiment  to  discover  their  peculiarities  and  their 
usefulness  in  forming  soaps. 

We  shall  describe  in  the  proper  places  the  secondary  sub- 
stances indispensable  in  this  manufacture,  giving  their  pro- 
perties and  mode  of  use,  but  it  will  be  unnecessary  to  detail 
all  their  chemical  properties,  as  such  descriptions  would 
take  unnecessary  space,  so  we  will  confine  ourselves  to  the 
properties  they  possess  when  applied  to  the  arts  of  making 
soap  and  candles. 

Yet  if  the  soap  maker  has  the  inclination  and  the  time  to 
study  all  the  chemical  properties  of  materials  he  may  use,  in 
fact  to  study  chemistry  generally,  it  would  be  of  great  ad- 
vantage and  add  much  interest  to  his  work  and  no  doubt 
result  in  a  great  improvement  to  his  w^ares. 

With  these  few  preliminary  remarks  we  will  proceed  to 
the  description  of  all  known  ingredients  and  materials  in  use 
for  making  soap. 

Potash.    Potasse,  Fr.    Kali,  Ger. 

Potash  was  at  first  called  fixed  vegetable  alkali,  because 
it  is  generally  obtained  from  the  ashes  of  many  plants.  It 
is  known  in  the  market  by  diftereut  names,  derived  from  the 


28 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


vegetables  which  furnish  it,  or  from  the  countries  it  comes 
from.  However,  vegetables  are  not  the  only  source  from 
which  potash  is  extracted.  A  great  part  of  the  minerals 
which  compose  the  crystalline  rocks  contain  it  in  variable 
quantities,  in  combination  with  different  acids,  principally 
silicic  acid.    Pure  potash  is  not  met  with  in  nature. 

However,  the  principal  source  of  potash  is  the  combustion 
of  vegetables.  The  presence  of  potash  in  vegetables  was  an 
enigma  for  a  long  time,  for  vegetables,  properly  so  called,  do 
not  create  potash  ;  but  they  liave  the  valuable  faculty  of 
borrowing  from  the  soil  and  manures  the  soluble  salts  they 
contain,  among  which  are  potash  and  soda,  combined  with 
various  acids,  and  especially  organic  acids.  During  the 
combustion  the  organic  acids  are  decomposed,  and  the  car- 
bonic acid  resulting  from  this  decomposition  combines  with 
potash  and  soda  to  form  subcarbonates  of  these  bases. 

Of  late  years  potash  has  been  procured  in  great  abundance 
from  the  salt-rocks  in  Stasst'urt,  in  Prussia,  and  Kalucz,  in 
Hungary,  principally  from  carnalite,  a  chloride  of  potassium 
and  magnesium.  The  magnesia  is  precipitated  from  the 
solution  with  hydrochloric  acid,  leaving  the  potassium  salt; 
the  chloride  of  potash  is  then  submitted  to  the  process  de- 
scribed for  the  production  of  caustic  soda  from  chloride  of 
soda  (Leblanc's  process),  and  caustic  potash  is  thus  produced 
in  quantities  that  have  almost  superseded,  on  the  continent, 
all  potashes  from  other  sources. 

Independently  of  the  carbonates  of  potash  and  soda,  the 
ashes  of  vegetables  contain  also  several  other  salts,  particu- 
larly the  chlorides  of  potassium  and  sodium,  sulphates  of 
potash  and  soda,  carbonates  and  phosphates  of  lime  and  mag- 
nesia, silicate  of  alumina,  and  a  certain  quantity  of  organic 
matters  not  decomposed,  which  color  the  saline  residuum 
obtained  by  the  lixiviation  of  the  ashes.  By  calcining  this 
residuum  to  redness  in  a  reverberatory  furnace,  white  potash 
is  obtained. 

We  must  here  make  an  important  observation.  Vegetables 
which  grow  on  the  sea-shore,  or  in  the  neighborhood  of  salt 
mines,  give  by  their  incineration  very  small  quantities  of 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  29 


potash  ;  they  principally  contain  soda.  Those,  on  the  con- 
trary, which  grow  inland  and  in  soils  free  from  chloride  of 
sodium,  yield,  by  their  combustion,  ashes  which  contain 
principally  carbonate  of  potash,  mixed  with  very  small  pro- 
portions of  soda.  These  vegetables  are  the  only  ones  em- 
ployed in  the  preparation  of  the  carbonate  of  potash. 

Independently  of  the  culture,  it  is  easily  demonstrated 
that  the  quantity  of  ashes  furnished  by  different  vegetables 
i^  not  identical.  It  varies  considerably  according  to  the 
different  species,  the  influence  of  climate,  and  particularly 
the  nature  of  the  soil  in  which  they  have  grown.  Experience 
also  proves  that  the  young  parts  of  the  i)lants,  in  which  cir- 
culates a  rich  and  abundant  sap,  are  those  which  contain  the 
greater  percentage  of  salts  of  potash.  It  is  thus  that  the 
leaves  of  a  tree  yield  more  potash  than  the  branches,  and 
these  more  than  the  body  of  the  tree. 

D'Arcet,  who  has  experimented  much  on  the  manufacture 
of  alkalies,  has  published  an  interesting  paper  on  the  extrac- 
tion of  potash  from  the  ashes  of  the  horsechestnut.  He  as- 
certained that  one  hundred  parts  of  dried  chestnuts  yielded 
nearly  half  their  weight  of  ashes  at  65  alkalimetric  degrees. 

The  following  table  gives  the  quantity  of  potash  contained 
in  certain  veoretables : — 


30 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Comparative  Table  of  the  Quantities  of  Ashes  and  Potash 
contained  in  different  Vegetables. 


Jfames  of  (he  vegetables. 

Quantity  of 

Quantity  of 

Chemist  who  made  the 

ashes. 

alkali. 

analysis. 

100  parts  of — 

Willow 

2.80000 

A  CiO  A  AA 

0.28400 

Kirwan. 

Elm  .... 

2.36727 

A  OAAAA 

0.39000 

Oak  .... 

1.35185 

0.15343 

Pertuis. 

Poplar 

•i             A  Tit* 

1.23476 

A  City  A  a 't 

0.07481 

Yoke-elm  . 

1.12830 

A  1  o  cr  /I  A 

0.12540 

Beech  .... 

0.58432 

0.14572 

Pitch-pine  tree  . 

0.31740 

A          1  OA 

0.73180 

de  Fontenelle. 

Vine  .... 

3.37900 

A  PrrirAAA 

O.SoOOO 

Kirwan. 

Stalks  of  corn 

8.86000 

1 . 75000 

Wormwood 

y.  74400 

tV  OAAAA 

7.30000 

Fumitory  . 

21.90000 

AAAAA 

7.90000 

Fumitory  . 

o2. 10000 

O  A  1  er AA 

8.  U 1500 

de  Fontenelle. 

Vines  of  hops 

1  A  ATkAAA 

10,00000 

O  A  1  cr  AA 

3.  U 1500 

Thillaye. 

Vines  of  Windsor  beans 

1  A  AAAAA 

A    1 OAAA 

4.  i/iyuu 

Common  nettle  . 

10.()71bo 

2.5U33U 

Pertuis. 

Common  thistle  . 

4.U42D0 

A  K0~0 i 

O.Oo  <o4 

Ferns  . 

O.UU  /81 

0.o2o9U 

Reed  .... 

3.85395 

0.72234 

Reed  .... 

3.33593 

0.50811 

Turnsole 

20.70000 

4.00000 

Genista 

3.00500 

1.30870 

de  Fontenelle. 

Heath  .... 

2.91090 

0.84000 

Stalks  of  corn 

9.35100 

2.00400 

( ( 

Erigeron  Canadense  . 

10.80000 

2.65200 

Bouillon  Lagrange. 

Horsechestnut  tree  bark 

18.46000 

4.84000 

de  Fontenelle. 

Centaury 

8.44000 

2.00800 

Kirwan. 

Burdock  leaves  . 

4.84000 

0.98400 

de  Fontenelle. 

Camomile  . 

5.63900 

1.80000 

Orange  leaves 

14.24000 

2.40400 

The  above  numbers  give  an  approximative  idea  of  the 
quantities  of  ashes  left  by  the  different  species  of  vegetables, 
but  these  numbers  are  not  absolute.  The  different  parts  of 
the  same  plants  do  not  yield  the  same  quantity  of  ashes,  as 
is  shown  by  the  following  table  : — 


Oak. 

Beech. 

Yoke-elm. 

Pine. 

.    .  6.00 

6.62 

13.4 

.    .  5.50 

2.60 

.    .  3.30 

0.61 

0.6 

1.19 

Ashes,  whatever  is  the  part  of  the  vegetable  w^hich  has 
furnished  them,  present  a  complex  composition,  variable 
with  each  species,  and  even  with  every  individual.  The 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  31 


compounds  they  contain  are,  some  soluble,  some  insoluble. 
The  first,  among  which  is  the  carbonate  of  potash,  are  the 
only  ones  employed  in  industry,  after  separating  them,  by 
washing,  from  the  insoluble  compounds.  The  relative  pro- 
portions of  the  soluble  and  insoluble  salts  present  great  dif- 
ferences, as  is  shown  in  the  following  table,  in  which  Berth ier 
has  given  the  quantities  per  cent,  of  soluble  and  insoluble 
matters. 


Substances  employed 

Soluble  parts 

Insoluble  parts 

to  produce  ashes. 

for  100  of  ashes. 

for  100  of  ashes. 

White  Beech 

.  19.33 

80.78 

Red  Beech 

.  16.30 

83.70 

Oak  .... 

.  13.00 

88.00 

Lime  tree  . 

.  10.80 

89.30 

Birch  tree  . 

.  16.00 

84.00 

Alder  tree  . 

.  18.80 

81.30 

Fir  tree 

.  35.70 

74.30 

Pine  .... 

.  13.60 

86.40 

75.00 

Walnut  tree 

.  15.40 

84.60 

Elderberry 

.  31.50 

68.50 

Straw  .... 

.  10.10 

89.90 

Stalks  of  Potatoes 

.  4.30 

95.80 

.  39.00 

71.00 

Among  the  insoluble  compounds,  the  carbonate  of  lime 
predominates:  after  being  well  washed  and  dried,  the  in- 
soluble residuum  does  not  contain  less  than  75  to  90  per 
cent,  of  its  weight  of  carbonate  of  lime;  the  phosphates  of 
lime  and  magnesia,  silica,  etc.,  are  the  compounds  which 
generally  accompany  it.  Their  proportion  varies  between 
the  limits  of  from  25  to  10  i)er  cent. 

Essentially  formed  of  carbonate  of  potash,  a  small  quantity 
of  sulphate  of  potash  and  chloride  of  potassium,  and  of  a  trace 
of  silicate  of  potash,  the  soluble  compounds  which  alone  have 
to  fix  our  attention  present,  in  the  relative  proportions  of 
these  different  salts,  variations  which  are  interesting  to 
notice.  The  following  table  enables  us  to  establish  the  com- 
position of  the  mixture  of  soluble  salts  extracted  from  the 
ashes  of  some  vegetables. 


32  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Birch. 

Yoke-elrn. 

Elm. 

Oak. 

Mulberry. 

Fir  tree. 

Carbonic  acid  .  . 

0.170 

0.247 

0.224 

0.240 

0.230 

0.123 

Sulphuric    "  .  . 

0.023 

0.073 

0.073 

0.081 

0.083 

0.069 

Chlorine .... 

U.uU-i 

U.UUl 

A  A  /I  A 

0.040 

O.OlO 

0.010 

0.010 

0.002 

0.020 

Potash  .... 

1  0.795 

0.507 
0.121 

j- 0.641 

0.676 

0.520 
0.115 

0.506 
0  282 

1.000 

1.005 

1.000 

1.000 

0.988 

1.000 

Such  are  the  principal  variations  in  their  composition  that 
the  different  veo^etable  species  present.  However,  whatever 
is  their  composition,  the  extraction  of  the  potash  is  effected 
in  the  same  manner.  The  ashes  remaining  after  the  com- 
bustion are  carefully  lixiviated,  and  furnish  liquors  which, 
evaporated  to  dryness,  yield  a  colored  residuum  called  saliyi. 
This,  by  a  simple  purification  by  fire,  is  transformed  into 
commercial  carbonate  of  potash. 

Extraction  of  Potash. 

The  industrial  fabrication  of  potash  from  ashes  is  carried  on 
only  in  countries  where  wood  is  abundant.  Thus  the  largest 
quantity  of  that  employed  in  the  arts,  comes  from  Russia  or 
from  this  country.  As  we  have  before  said,  vegetables  when 
fully  developed  contain  a  smaller  proportion  of  salts  of 
potash  than  when  their  vegetation  is  less  advanced.  Start- 
ing from  this  principle,  confirmed  by  experience,  branches, 
small  trees,  and  herbaceous  plants  must  be  preferred,  as  being 
richer  in  salts  of  potash.  If  the  operation  is  conducted  with 
the  latter  vegetables,  they  are  to  be  cut  carefully,  and  spread 
on  a  dry  and  smooth  place,  where  they  are  left  until  com- 
pletely dried;  after  their  desiccation,  they  are  collected  and 
put  into  heaps,  near  by  the  place  where  they  are  to  be 
burned.  In  damp  countries  they  are  dried  under  large 
sheds.  When  trees  are  burned  for  the  purpose  of  extracting 
potash,  they  are  divided  into  large  pieces  and  dried  in  the 
open  air. 

The  processes  of  combustion  are  not  the  same  in  every 
country.    Formerly,  and  even  yet  in  some  localities,  the 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  83 


combustion  was  eft'ected  on  the  ground.  For  this  purpose 
an  open  place  is  selected,  and  several  heaps  of  plants  are 
formed,  and  are  set  on  fire ;  as  fast  as  the  combustion  takes 
place,  new  plants  are  added.  When  they  are  all  burned,  let 
the  ashes  cool,  then  spread  them  under  sheds  where  they  are 
exposed  to  the  air  for  a  few  days,  so  that  all  the  potash  they 
contain  may  be  transformed  into  the  carbonate  by  absorbing 
carbonic  acid  from  the  air.  The  ashes  are  then  lixiviated 
with  water,  in  wooden  or  in  cast-iron  vats.  The  liquors  are 
afterwards  evaporated  to  dryness  in  cast-iron  kettles.  The 
crude  potash,  resulting  from  this  evaporation,  is  bleached  and 
granulated  in  a  reverberating  furnace. 

Combustion  of  the  Plants  in  Furnaces, — The  combustion  in 
furnaces,  now  in  use  in  several  manufactories,  gives  a  larger 
quantity  of  ashes,  the  incineration  of  which  is  more  complete 
than  when  the  combustion  takes  place  in  the  open  air. 

By  this  process,  the  combustion  of  the  plants  is  conducted 
in  furnaces  made  of  refractory  bricks;  they  are  provided,  at 
their  lower  part,  with  a  cast-iron  grate,  under  which  is  a 
large  ash-pan,  also  made  of  bricks,  the  object  of  which  is  to  re- 
ceive the  ashes  from  the  incineration  of  the  plants.  To  render 
the  combustion  more  uniform  and  complete,  pipes  disposed 
around  the  base  of  the  furnace,  bring  cold  air  under  the 
grate.  To  preserve  the  inside  of  the  furnace  from  the  de- 
structive action  of  the  fire,  the  bricks  are  covered  with  a 
coating  of  clay  about  one-third  of  an  inch  thick,  which, 
before  beginning  the  operation,  is  allowed  to  dry  for  several 
days. 

All  the  preliminaries  being  arranged,  throw  on  the  grate 
a  few  armfuls  of  dry  plants,  and  set  them  on  fire ;  when  the 
combustion  is  well  established,  feed  the  fire  with  new  loads 
of  materials,  which  are  proportioned  to  the  intensity  of  the 
combustion,  which  ought  to  be  neither  too  slow  nor  too 
rapid.  In  the  latter  case,  a  too  rapid  combustion  will  occa- 
sion a  certain  loss  of  alkali,  which  volatilizes;  in  the  first 
case,  the  operation  if  too  much  prolonged,  becomes  difficult, 
and  gives  imperfect  results,  because  there  is  always  a  certain 
quantity  of  organic  matter  which  is  not  burned;  but  by 
3 


34 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


practice,  the  operation  may  be  regulated  at  will  by  means  of 
the  pipes  which  bring  cold  air  under  the  grate.  When  the 
combustion  is  too  rapid,  slacken  it  by  closing  the  pipes ; 
when  too  slow,  allow  the  cold  air  to  come  under  the  grate. 

The  operation  is  well  established  only  after  a  few  hours. 
To  obtain  a  complete  incineration,  stir  the  fuel  from  time  to 
time  with  a  long  iron  rod,  so  as  to  permit  the  fire  to  act 
equally  on  the  entire  mass.  When  the  vegetables  are  too 
damp,  they  sometimes  form  agglomerations  of  ashes  on  the 
grate,  which  render  the  combustion  slower;  to  destroy  these 
agglomerations  and  give  a  new  start  to  the  combustion,  pass 
an  iron  hook  between  the  bars  of  the  grate. 

During  all  the  time  of  the  operation,  the  ashes  which  are 
produced  fall  in  the  form  of  powder  into  the  ash-pan  placed 
under  the  grate,  from  w^hich,  when  they  have  filled  the  pan 
about  three-fourths  full,  they  are  taken  with  a  shovel  and 
carried  into  a  building,  where  they  are  spread  on  the  ground 
in  beds  three  or  four  inches  thick.  From  time  to  time  the 
surface  is  stirred,  so  as  to  assist  the  transformation  of  the 
potash  into  carbonate.  It  is  to  facilitate  this  reaction,  that 
ashes  recently  calcined  are  exposed  to  the  air  for  a  few  days 
before  being  lixiviated. 

Leaching  or  Washing  of  the  Ashes. — This  operation  has  for 
its  object  the  extraction  of  the  carbonate  of  potash,  existing 
in  the  ashes.  To  proceed,  use  wooden  or  sheet-iron  vats,  of 
a  capacity  of  200  to  250  gallons — generally  8  or  10  are  dis- 
posed one  over  the  other;  they  receive  the  name  of  barrel ; 
the  number  of  barrels  varies  according  to  the  importance  of 
the  fabrication.  Each  vat  is  provided  with  a  double  bottom 
covered  with  a  strainer  which  acts  as  a  filter.  By  this 
means  clear  and  limpid  lyes  are  obtained.  These  vats  have, 
at  the  bottom,  a  cock  to  draw  ofi:'the  lye. 

The  vats  being  thus  disposed,  charge  them  to  four  fifths  of 
their  capacity  with  ashes,  and  pour  on  them  a  quantity  of 
water  sufticient  to  cover  them  entirely.  After  standing  from 
fifteen  to  eighteen  hours,  open  the  cocks,  and  collect  the  lye 
in  a  special  receiver.  By  using  this  lye  instead  of  water  for 
the  treatment  of  new  ashes,  we  obtain  after  twelve  or  fifteen 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  35 


hours  of  reaction,  a  new  lye  markino^  from  10°  to  12°  Baume, 
which  can  be  brought  up  to  15°  or  18°  by  successive  passages 
through  new  ashes;  but  this  method,  which  is  long  and 
costly,  is  not  much  employed,  the  manufacturer  generally 
preferring  to  have  liquors  at  10°  or  lz°. 

Continue  the  lixiviation  of  the  ashes  by  successive  wash- 
ings with  pure  water.  It  is  ascertained  that  the  material  is 
completely  exhausted  when  the  liquid  has  lost  all  alkaline 
taste,  but  there  is  a  more  exact  process,  which  is  to  collect 
some  of  the  liquid  and  try  it  with  the  areometer.  The  in- 
strument will  descend  to  0°  if  the  ashes  are  completely  ex- 
hausted. The  lye  thus  obtained,  besides  the  foreign  salts, 
contains  the  carbonate  of  potash  in  solution;  it  is  generally 
colored  brown,  due  to  a  small  quantity  of  organic  matter, 
which  has  escaped  the  combustion. 

The  liquors  marking  from  10°  to  12°  are  evaporated  in  a 
series  of  cast-iron  kettles  heated  by  the  same  hearth.  The 
evaporated  water  is  replaced  by  the  addition  of  fresh  liquors. 
When  the  lyes  have  acquired  a  syrupy  consistency,  they  are 
evaporated  to  dryness  in  a  thick  cast-iron  kettle.  The  opera- 
tion is  finished  when  the  substance  becomes  dry  and  friable. 

The  crude  potash  thus  obtained  is  strongly  colored  brown. 
To  bleach  it,  it  is  placed  in  a  reverberatory  furnace,  heated 
to  whiteness.  Towards  the  end  of  the  operation,  the  tem- 
perature is  raised  enough  to  redden  the  salt,  expel  the  water, 
and  destroy  the  organic  matter  which  colors  it.  It  is,  how- 
ever, very  essential,  that  the  temperature  should  not  be  too 
high,  for  then  the  potash  would  experience  a  kind  of  vitrifi- 
cation which  would  render  it  heavy  and  difiicult  to  dissolve 
in  water.  When  the  potash  has  become  white,  that  is  the 
moment  to  take  it  from  the  furnace.  Potash  well  prepared 
is  light,  porous,  and  strongly  alkaline.  Exposed  to  the  air, 
it  attracts  moisture  and  becomes  deliquescent.  The  loss  ex- 
perienced by  the  crude  potash,  when  calcined,  is  about  fif- 
teen per  cent. 

Hed  American  Potash. — Potash  deprived  of  carbonic  acid 
by  lime  has  received  the  name  of  caustic  potash.    All  com- 


36  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


mercial  potashes  may  be  transformed  into  caustic  potash  by 
the  following  process  : — 

In  a  large  iron  kettle,  heat  250  gallons  of  water,  which 
raise  quickl^^  to  the  boiling  point;  add,  in  successive  doses, 
400  pounds  of  carbonate  of  potash,  and  stir  the  mixture  to 
facilitate  the  solution.  When  the  salt  is  entirely  melted, 
pour  into  the  kettle,  in  portions,  200  pounds  of  quicklime, 
previously  mixed  with  double  its  weight  of  water,  and  boil 
the  mixture  for  two  or  three  hours.  The  lime  combines  with 
the  carbonic  acid  which  is  united  to  the  potash,  and  forms 
an  insoluble  carbonate  of  lime,  while  the  caustic  potash  re- 
mains in  solution  in  the  liquor.  After  a  settling  of  18  or 
20  hours,  decant  the  clear  liquor  carefully,  without  disturb- 
ing the  lime  which  is  at  the  bottom  of  the  kettle,  and  this 
liquor  is  rapidly  evaporated  to  dryness  in  cast-iron  kettles. 
The  crude  potash  obtained  is  heated  to  redness  in  a  thick 
cast-iron  kettle,  so  as  to  melt  it.  To  give  this  substance  the 
red  color,  characteristic  of  the  caustic  American  potash,  add 
to  the  melted  mass  one  per  cent,  of  protoxide  of  copper,  the 
oxidation  of  which  is  determined  by  srnall  proportions  of 
saltpetre.  When  the  shade  is  obtained,  run  the  melted  mass 
into  small  cast-iron  kettles,  in  which  it  becomes  very  hard 
by  cooling. 

This  is  the  usual  process  of  manufacturing  caustic  potash ; 
but  in  this  country  it  is  conducted  more  economically. 
The  ashes  are  directly  treated  by  lime,  and  the  mixture  is 
lixiviated  by  water.  Lyes  in  a  caustic  state  are  obtained, 
and  are  concentrated  to  dryness,  and  the  mass  is  melted  as 
we  have  seen. 

American  potash  is  very  caustic,  and  quickly  attracts  the 
moisture  of  the  air.  It  is  much  used  in  the  industries,  prin- 
cipally in  the  fabrication  of  soft  soap. 

In  Paris  is  manufactured  a  fictitious  article,  which  must 
not  be  confounded  with  the  American  potash.  The  latter 
has  really  potash  for  a  base,  while  the  first  is  a  mixture  of 
caustic  soda,  salt,  and  sulphate  of  potash.  The  materials  are 
melted  together,  and  are  colored  red  with  oxide  of  copper. 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  37 


Fictitious  potash  is  distinguished  by  a  very  strong  saline 
taste,  which  American  potash  does  not  possess. 

Ashes  made  from  Tartar. — These  ashes  are  prepared  only  in 
countries  where  wine  is  made,  and  can  be  produced  advan- 
tageously in  California,  Ohio,  ITew  Jersey,  and  other  States 
where  the  culture  of  the  vine  is  advanced. 

This  alkali,  the  purest  found  in  commerce,  is  obtained  by 
the  calcination  of  the  dregs  of  wine.  To  produce  the  com- 
bustion of  these  dregs,  it  is  essential  to  have  them  perfectly 
dry.  To  obtain  them  in  this  state,  they  are  introduced  into 
cotton  bags,  then  submitted  to  a  graduated  but  energetic 
pressure,  so  as  to  extract  the  wine  they  contain.  This  wine 
is  generally  very  acid,  and  is  used  to  make  vinegar.  After 
the  pressure,  break  the  cakes  into*  pieces,  and  expose  them 
for  some  time  to  the  air  to  dry ;  then  burn  them  in  large 
furnaces  havino;  a  circular  form.  Like  all  veoretable  salts 
with  potash  for  a  base,  the  lees  of  wine  give  carbonate  of 
potash  by  calcination.  This  salt  results  from  the  decompo- 
sition of  the  tartrate  of  potash  contained  in  the  dregs. 

When  carefully  manufactured,  the  ashes  of  dregs  give  one 
of  the  best  commercial  potashes.  In  this  state  they  contain 
only  a  very  small  proportion  of  chloride  of  potassium  and 
sulphate  of  potash.  This  alkali  is  generally  in  a  porous  and 
light  mass,  having  a  greenish  color  with  blue  veins.  This 
color  is  due  to  the  oxides  of  iron  and  manganese.  Pure 
ashes  dissolve  almost  entirely  in  water,  and  leave  only  a 
residuum  of  7  to  8  per  cent,  of  insoluble  matters.  200  pounds 
of  good  dregs,  perfectly  dry,  produce  from  10  to  12  pounds 
of  ashes,  the  titer  of  which  varies  between  25  and  33  alkali- 
metric  degrees.  When  the  dregs  contain  much  tartrate  of 
potash,  they  give,  by  their  combustion,  an  alkali  of  a  much 
higher  titer.  The  white  potash  is  obtained  by  treating  the 
ashes  by  water,  which  dissolves  the  soluble  salts,  and 
amongst  them  the  carbonate  of  potash.  The  lye  is  evapo- 
rated to  dryness,  and  the  mass  is  bleached  in  a  reverberatory 
furnace.  By  this  refining,  ashes  give  about  half  of  their 
weight  of  white  potash.  But  it  is  generally  in  the  form  of 
ashes  that  this  alkali  is  found  in  commerce. 


38 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Potash  made  from  Bed-root  Molasses, — Chemical  analysis 
has  long  since  demonstrated  that  the  salts  of  potash  exist  in 
a  large  proportion  in  heet-root  molasses.  This  fact  has  found 
a  useful  application  in  industry.  It  is  to  M.  Dubrunfault 
that  is  due  the  discovery  of  the  processes  for  extracting 
potash  from  the  saline  residues  left  after  the  distillation  of 
the  molasses,  which  is  extensively  used  in  the  production 
of  alcohol.  It  is  from  the  saline  residues  that  potash  is 
obtained.  Potash,  being  undecomposable  in  the  conditions 
in  which  the  operation  takes  place,  is  found,  after  the  de- 
composition of  the  sugar  by  fermentation  and  the  extraction 
of  the  alcohol  by  distillation,  in  the  liquid  residuum.  It 
is  extracted  from  this  residuum  by  evaporating  the  water, 
and  by  the  incineration  of  the  concentrated  residuum.  The 
product  of  the  incineration  constitutes  a  light,  porous,  and 
friable  mass.  It  is  crude  potash  ;  its  titer  is  from  40  to  50 
alkalimetric  degrees.  The  white  potash  is  obtained  by  lixi- 
viating the  crude  potash  in  sheet-iron  filters  having  a 
cylindrical  form.  The  exhaustion  takes  place  with  warm  or 
cold  water;  the  use  of  warm  water  is  more  advantageous, 
but  it  dissolves  some  of  the  sulphuret.  Cold  water  gives  a 
purer  product,  but  the  operation  takes  longer,  and  the  re- 
siduum is  not  so  well  exhausted  of  its  alkali. 

The  lyes  marking  from  25°  to  30°  Baume  are  evaporated 
in  cast-iron  kettles  until  they  mark  from  45°  to  46°.  They 
are  poured  while  boiling  into  sheet-iron  vats;  and  after  eight 
or  ten  days,  a  very  abundant  crystallization  of  different  salts 
is  obtained.  Among  the  crystals  we  meet  chloride  of  potas- 
sium, and  the  larger  part  of  the  carbonate  of  soda,  which 
was  dissolved  in  the  lyes. 

The  mother  liquors  are  very  rich  in  carbonate  of  potash. 
To  extract  this  salt,  they  are  concentrated  in  cast-iron  kettles 
with  flat  bottoms,  until  they  are  reduced  to  a  syrupy  con- 
sistency. By  continuing  the  operation,  the  mass  swells 
considerably,  and  becomes  dry  and  friable.  The  drying  is 
accelerated  by  stirring  with  an  iron  stirrer.  Thus  obtained, 
the  potash  is  not  pure,  but  is  mixed  with  extractive  matters, 
which  color  it;  it  contains  besides  from  twelve  to  eighteen 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  39 


per  cent,  of  water.  To  bring  it  to  a  commercial  state,  it  is 
calcined  in  a  reverberatory  furnace.  This  last  operation 
destroys  the  coloring  matter  and  drives  off  the  excess  of 
water  with  which  it  was  combined. 

Potash  thus  prepared  is  very  white;  it  is  one  of  the  best 
and  richest  found  in  commerce  ;  it  is  advantageously  em- 
ployed in  the  fabrication  of  soft  soaps,  and  according  to 
several  manufacturers,  it  is  preferable  to  any  other,  because 
it  gives  more  consistency  to  the  soap.  This  effect  is  proba- 
bly due  to  the  presence  of  a  certain  quantity  of  soda. 

Composition  of  Commercial  Potashes. — Carbonate  of  potash 
is  the  base  of  the  commercial  potashes,  but  besides  this  salt, 
they  contain  several  others,  and  principally  more  or  less 
considerable  proportions  of  sulphate  of  potash  and  chloride  of 
potassium.  The  presence  of  these  salts  is  demonstrated  by 
dissolving  half  an  ounce  of  potash  in  3J-  ounces  of  distilled 
water;  the  solution  is  saturated  by  acetic  or  pure  nitric 
acid.  After  the  saturation,  filter  and  divide  the  filtrate  in 
two  portions,  which  are  separately  submitted  to  the  follow- 
in  o;  reaofcnts: — 

1.  If,  into  one  part  of  the  liquor,  chloride  of  barium  is 
poured,  an  abundant  white  precepitate,  insoluble  in  nitric 
acid,  is  formed.  This  precipitate  is  sulphate  of  baryta, 
which  indicates  that  the  carbonate  of  potash  contains  a 
sulphate. 

2.  If,  into  the  other  part  of  the  liquor,  we  pour  a  solution 
of  nitrate  of  silver,  a  white  precipitate,  insoluble  in  nitric 
acid,  soluble  in  ammonia,  is  formed.  This  precipitate  is 
chloride  of  silver,  and  indicates  that  the  potash  contains  a 
chloride. 

The  same  methods  may  be  employed  to  detect  sulphates 
and  chlorides  in  crude  sodas. 

The  most  esteemed  potashes  are  those  of  America,  Russia, 
Tuscany,  Dantzick,  and  particularly  that  made  in  France 
from  beet  molasses. 

The  following  table  gives  the  composition  of  the  principal 
commercial  potashes.  The  free  potash  and  soda  are  repre- 
sented by  their  equivalent  in  pure  carbonate. 


40  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Potash 

Potash 

Pota.«h  of 

Potash  of 

Potash 

Potash 

of 

of 

America 

America 

of  the 

of 

Tuscany. 

Russiji, 

(red). 

(pearl  ash) 

Vosges. 

molasses. 

Potassium  sulphate  . 

13.47 

14.11 

15.32 

14.38 

38.84 

1.197 

Potassium  chloride  . 

0.95 

2.09 

8.15 

3.64 

9.16 

4.160 

Potassium  carbonate. 

74.10 

69.61 

68.04 

71.38 

38.63 

76.440 

lOOLlltllll  C-Cll  U^JllCllC  •  * 

3.00 

3.09 

5.85 

2.31 

4.17 

16.330 

Hygrometric  Avater  . 

7^28 

8!82 

4^56 

5.34 

0.624 

Insoluble  substances  > 
and  loss    .    .    .  i 

1.20 

2.28 

2.64 

3.73 

3.86 

1.249 

100.00 

100.00 

100.00 

100.00 

100.00 

100.000 

Alkalimetric  degrees 

56.0 

53.1 

55.0 

54.4 

31.6 

69.3 

We  see,  by  the  above  table,  that  independently  of  the  sul- 
phates and  chlorides,  all  potashes  contain  soda  in  variable 
proportions;  the  American  potash  is  that  which  contains 
the  least,  and  that  of  molasses  contains  the  most.  The  in- 
soluble residuum  is  partly  composed  of  carbonates  and 
phosphates  of  lime  and  magnesia,  silicate  of  alumina,  and 
the  oxides  of  manganese  and  iron.  The  first  of  these  oxides 
colors  them  blue,  the  second  communicates  to  them  a  red 
shade. 

Purification  of  Potash. — It  is  easy  to  separate  from  potash 
the  greater  part  of  the  sulphate  it  contains.  It  is  sufficient 
to  dissolve  it  in  the  least  possible  quantity  of  water.  The 
sulphate,  much  less  soluble  than  the  carbonate,  remains  un- 
dissolved ;  it  is  stirred  several  times  with  water,  w^hich  dis- 
solves the  alkali.  This  solution  is  used  to  dissolve  a  new 
quantity  of  potash.  The  sulphate  washed  and  dried  is  sold 
for  about  half  the  price  of  the  potash  itself,  and  as  that  sul- 
phate has  no  useful  effect  when  mixed  with  potash,  it  is 
better  to  extract  it  and  sell  it  separately. 

The  chloride  of  potassium,  very  slightly  soluble  in  a  liquid 
saturated  with  carbonate  of  potash,  is  partly  separated  by 
the  same  process. 

The  solutions  obtained  at  45°,  by  this  process,  are  evapo- 
rated in  kettles  of  gradually  decreasing  depth. 

It  is  into  the  deepest  kettle,  directly  heated,  that  the 
liquid  is  introduced :  as  fast  as  the  evaporation  reduces  the 
volume,  fill  the  kettle  with  the  solution,  and  the  other 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  41 


kettles  with  the  solutions  already  concentrated  in  each 
preceding  kettle.  In  this  way,  as  fast  as  the  solution  con- 
centrates and  retains  the  water  with  more  tenacity,  it  is 
placed  in  a  flatter  vessel,  in  which  the  stirring  is  more  easily 
eftected,  and  the  column  of  liquid  being  of  less  height  above 
the  bottom,  the  saline  incrustations,  which  w^ould  be  an 
obstacle  to  the  passage  of  heat,  do  not  form  so  easily.  The 
desiccation  is  achieved  in  the  latter  kettle,  w^iich  is  flatter. 

The  carbonate  of  potash,  economically  purifled  by  this 
process,  is  used  in  the  arts  requiring  a  purer  product  than 
commercial  potash.  Wherever  wood-ashes  can  be  bought  at 
reasonable  prices  for  the  manufacture  of  soft  soaps,  a  large 
saving  is  attained  and  they  deserve  far  more  consideration 
than  has  hitherto  been  given  them.  Under  favorable  condi- 
tions the  lye  produced  from  wood-ashes  will  cost  but  one- 
half,  often  but  one-third  of  the  price  of  that  made  of  potash. 
The  reason  for  this  is  partly  found  in  this,  that  by  the  home 
manufacture  of  potash  in  the  form  of  lye,  both  the  cost  of 
boiling  and  calcination  as  well  as  the  expense  of  transportation 
will  be  saved.  The  supply  from  this  source  is  constantly 
diminishing,  and  recently  commerce  has  been  supplied  from 
new  sources.  The  rock-salt  mines  and  the  beet-sugar  fac- 
tories have  become  the  most  reliable.  Their  potashes  are 
richer  in  alkali  and  freer  from  impurities,  and  are  from  this 
fact  more  desirable,  requiring  much  less  labor  in  the  prepa- 
ration of  the  lyes. 

For  the  proper  tests  for  potash  the  reader  must  turn  to 
Alkaliraetry, 

Soda.    Sonde,  Fr.    Natron,  Ger. 

Soda,  the  base  of  all  hard  soaps,  exists  in  nature  in  the 
waters  of  various  lakes  and  springs  in  many  parts  of  the 
world,  and  the  ashes  of  marine  plants,  w^hich  were  formerly 
the  source  of  all  commercial  soda.  But  since  the  discovery 
and  manufacture  of  artificial  soda  from  culinary  salt,  that 
is  in  general  use  for  making  soaps,  and  being  furnished 
comparatively  pure,  and  in  a  caustic  and  concentrated  form, 


42 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


there  is  a  saving  of  much  labor  and  cost  for  plant  outlay.  The 
caustic  sodas  of  commerce  are  generally  sufficiently  pure  for 
all  ordinary  soaps  of  commerce,  though  for  superior  toilet 
soaps  the  lye  should  be  perfectly  pure.  The  soap  maker  will 
find  it  necessary  to  make  his  own  lye,  and  that  from  the 
crystallized  carbonate  of  soda  made  caustic  with  the  hydrate 
of  lime  is  the  most  reliable. 

Chemically  pure  soda  is  composed  of  sodium  and  oxygen, 
but  is  never  found  in  this  state  in  nature;  it  is  always  in 
combination  either  with  chlorine,  with  which  it  forms  chlo- 
ride of  sodium  (common  salt),  or  with  acids,  principally 
carbonic  acid.  With  this  latter  it  forms  the  carbonate  of 
soda.  This  salt  is  met  with  abundantly  in  several  countries 
of  the  world,  and  particularly  in  the  East,  where  it  has  been 
known  for  a  long  time  by  the  name  of  natron. 

Natural  sodas  are  the  carbonates  of  soda,  obtained  by  the 
incineration  of  several  species  of  plants  growing  on  .the  sea- 
shore. These  plants  furnish  very  variable  proportions  of 
carbonate  of  soda  mixed  with  different  salts.  Those  which 
give  the  most  are :  the  Salsola  soda^  and  the  Salicornia 
^iiropoea. 

During  their  vegetation,  the  plants  draw  from  the  soil  the 
salt  it  contains,  and  assimilate  the  soda,  which  they  trans- 
form, at  least  partially,  into  organic  salts,  principally  in 
acetates  and  oxalates,  decomposable  by  heat.  Gay-Lussac 
ascertained  by  analysis,  that  the  salsola  soda  contained  a 
considerable  proportion  of  oxalate  of  soda.  When  these 
plants  are  burned,  the  organic  acids  are  destroyed,  and  the 
carbonic  acid  resulting  from  the  combustion  combines  with 
the  soda  to  form  a  carbonate.  Sodas  take  their  names  from 
the  countries  which  produce  them. 

Soda  of  Narbonne. — This  soda,  more  generally  known  by 
the  name  of  salim\  is  the  best  manufactured  in  France.  It 
is  the  richest  in  pure  or  carbonated  soda,  which  is  the  only 
useful  alkali  for  the  preparation  of  solid  soaps.  The  plant 
which  produces  it  is  designated  by  the  name  of  salicorna 
annua.  The  plant  is  cultivated  in  several  parts  of  the  south 
of  France.    The  plant  is  cut  before  its  complete  maturity  ; 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  43 


is  spread  in  the  sun  to  dry,  and  then  incinerated.  Good 
salicors  give  from  20  to  25  per  cent,  of  carbonate  of  soda. 

Soda  of  Aigues-Mortes. — This  soda  is  prepared  in  the  neigh- 
borhood of  Aigues-Mortes.  It  is  obtained  by  the  incinera- 
tion of  very  different  plants  growing  naturally  and  without 
cultivation,  on  the  shores  of  the  Mediterranean.  These 
plants  are  collected,  dried,  and  burned  on  the  ground,  or  in 
proper  furnaces.  This  soda  is  found  as  a  black  and  compact 
half-melted  mass.  It  contains  a  large  proportion  of  common 
salt.  Its  richness  in  carbonate  of  soda  is  about  8  to  10  per 
cent. 

Soda  from,  Sea-weeds. — This  soda,  prepared  for  a  very  long 
time  on  the  coasts  of  l^ormandy  and  Brittany,  varies 
greatly  in  its  composition.  It  is  furnished  either  by  sea- 
weeds, or  by  plants  designated  by  botanists  under  the  names 
of  fucus  marilimus^  vesicidos  habejis,  and  commonly  called 
goemon.  These  plants  are  collected  at  low  tide,  dried  in  the 
sun,  and  calcined.  The  residuum  is  a  black  mass,  often 
porous,  and  is  called  kelp-soda.  This  soda  is  not  very  rich  in 
carbonate,  for  its  proportion  is  never  above  5  per  cent. ;  it 
generally  contains  only  from  2  to  3.  It  is  most  valuable  on* 
account  of  the  bromine  and  iodine  it  contains. 

Spanish  Sodas. — Prior  to  the  present  century,  Spain  fur- 
nished, under  the  names  of  sodas  of  Alicante,  Malaga,  and 
Carthagena,  the  greater  part  of  the  carbonate  of  soda  used  in 
Europe.  Among  the  numerous  varieties  of  Spanish  sodas, 
three  kinds  are  principally  distinguished  in  the  market ; 
they  are  known  by  the  names  of  barilla,  mixed,  and  salted 
barilla. 

The  first,  which  is  the  richest  in  pure  alkali,  and  conse- 
quently the  most  valuable,  is  furnished  by  the  plant  known 
by  the  name  of  salsola  soda.  When  the  plant  has  attained 
its  full  growth,  it  is  cut  and  dried  in  the  sun,  and  incine- 
rated in  cylindrical  pits  dug  in  the  ground,  about  five  feet 
deep.  To  begin  the  operation,  a  few  armfuls  of  dry  material 
are  thrown  into  the  pit,  and  ignited.  The  combustion  is 
kept  up  by  adding  little  by  little  new  dry  plants  and  is 


44:  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


accelerated  by  stirring  the  mass  from  time  to  time  with  an 
iron  rod.  This  operation  lasts  about  four  days,  and  is 
finished  when  the  pit  is  filled  to  two-thirds  or  three-fourths 
of  its  depth  with  the  products  of  the  combustion.  A  few 
days  after,  the  residuum  is  taken  out,  then  broken  into  large 
pieces  and  put  into  barrels. 

The  soda  thus  obtained  is  called  soft  barilla  ;  it  is  a  hard 
and  compact  mass,  of  a  gray-ash  color.  Eecently  prepared, 
its  fracture  is  smooth. 

Mixed  Barilla. — Mixed  barilla  is  obtained  in  the  same 
manner  as  the  above,  by  the  combustion  of  certain  marine 
plants  growing  on  the  shores  of  the  Mediterranean.  The 
only  difference  between  these  two  kinds  is  that  the  first  is 
manufactured  only  from  choice  plants,  carefully  cultivated 
and  free  from  weeds  ;  on  the  contrary,  the  mixed  barilla  is 
prepared  with  plants  not  so  well  cultivated,  which  grow  in 
grounds  nearer  the  sea — it  is  used  to  manufacture  solid  soaps. 

Salted  Barilla, — This  kind  differs  from  the  two  above 
named  by  the  strong  proportion  of  neutral  salts  it  contains, 
and  by  being  less  alkaline.  The  plants  which  produce  it  grow 
without  cultivation  on  the  sea-shore  in  soils  strongly  impreg- 
nated with  salt.  During  their  growth,  these  plants  absorb  a 
large  quantity  of  salt,  which  is  found  in  the  ashes  after  the 
incineration.  Although  less  pure,  less  alkaline,  and  less 
esteemed  than  the  two  last  described,  the  salted  barilla  is 
still  of  great  use  in  the  manufacture  of  Marseilles  soap.  Its 
blackish  color,  and  its  being  more  highly  sulphuretted 
than  the  others,  together  with  the  large  proportion  of  salt  it 
contains,  cause  it  to  play,  in  the  fabrication  of  marbled 
soap,  the  same  part  as  salted  soda.  The  blue  of  the  marbling 
is  brighter  and  more  intense,  it  progressively  contracts  the 
molecules  of  the  soap,  and  during  the  operation  keeps  it 
constantly  separated  from  the  lyes.  But  since  the  discovery 
of  artificial  soda  its  use  is  limited. 

Natron. — Is  a  natural  sesqui-carbonate  of  soda,  abundantly 
found  in  several  parts  of  the  world,  and  particularly  in 
Egypt. 

Egyptian  natron  is  now  extracted  from  two  lakes,  one 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  45 


near  Cairo,  and  the  other  a  short  distance  from  Alexandria. 
During  winter  these  lakes  are  filled  with  a  water  of  a  violet- 
red  color,  which  passes  by  infiltration  through  the  soil  of  the 
surrounding  hills.  During  its  course  it  runs  through  a  soil  in 
which  salt  and  carbonate  of  lime  are  abundant.  By  the 
contact  of  the  water,  a  spontaneous  reaction  takes  place 
between  these  two  salts,  wdiich  are  reciprocally  decomposed. 
Deliquescent  chloride  of  calcium  is  formed,  wdiich  infiltrates 
into  the  lower  part  of  the  soil,  and  the  sesqui-carbonate  of 
soda  efiloresces  at  the  surface.  This  double  decomposition  is 
considerably  favored  by  the  dampness  of  the  soil  and  the 
heat  of  the  climate.  Rain  water  or  w^aters  which  exude 
from  the  soil  dissolve  the  efflorescence  of  carbonate  of  soda, 
and  flow  into  the  lakes  in  which  they  reach  a  height  of  about 
six  feet.  These  lakes  are  from  thirteen  and  a  half  to  fifteen 
miles  in  length,  and  about  three-quarters  of  a  mile  in  width. 
The  bottom  is  stony  and  solid.  During  the  great  heat  of 
the  summer,  these  waters  concentrate  and  evaporate,  and  the 
natron  deposits  on  the  soil,  from  which  it  is  extracted  in 
gray  crystalline  plates,  which  are  purified  and  bleached  by 
successive  solutions  and  crystallizations. 

Commercial  natron  is  in  mass  or  in  plates,  with  a  grayish- 
white  color.  Its  fracture  is  granular  or  crystalline,  and  it 
contains  from  20  to  30  per  cent,  of  pure  soda.  In  very  dry 
years  these  lakes  furnish  about  450,000  lbs.  of  natron. 

In  Hungary,  and  certain  parts  of  South  America,  there 
are  siniilar  lakes  furnishing,  during  the  summer,  an  abun- 
dant efflorescence  of  sesqui-carbonate  of  soda.  Matron  is  also 
collected  in  some  of  the  lakes  around  Tripoli,  but  it  is  not  so 
abundant  as  in  the  lakes  of  Egypt,  although  the  product  is 
purer. 

History  of  the  Fabrication  of  Artificial  Soda. — The  discovery 
of  the  process  for  the  manufacture  of  soda  from  chloride  of 
sodium  has  exercised  on  the  progress  of  modern  industry  so 
powerful  an  influence,  that  it  is  necessary  here  to  dwell  upon 
the  circumstances  under  which  it  was  produced.  The  pri- 
ority of  this  discovery  has  never  been  successfully  contested, 
and  the  name  of  Leblanc,  to  whom  it  is  due,  is  now  known 


46 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


all  over  the  world;  however,  on  many  points  of  detail,  some 
doubts  existed,  which  have  only  recently  been  explained.  In 
1856,  M.  Dumas  presented  to  the  Academie  des  Sciences^  a 
paper  which  definitely  established  the  true  history  of  this 
important  question. 

Long  since,  the  old  Academy  of  Sciences  had  offered  a 
prize  of  2400  francs  ($480)  for  the  conversion  of  chloride  of 
sodium  into  carbonate  of  soda.  Father  Malherbe,  in  1777, 
was  the  first  who  thought  that  he  had  attained  the  indus- 
trial solution  of  the  problem ;  he  proposed  to  convert  first 
the  salt  into  sulphate  of  soda,  and  then  to  heat  this  salt  with 
charcoal  and  iron.  Macquer  and  Montigny,  in  1778,  made 
a  favorable  report  on  this  work.  Guyton  de  Morveau,  as- 
sociated with  Carny,  had,  a  few  years  before,  erected  an 
establishment  at  Croisie,  in  which  the  salt,  being  mixed 
with  lime,  was  afterwards  allowed  to  rest  in  contact  with  the 
air.  Very  soon  the  carbonate  of  soda  effloresced  on  the  sur- 
face of  the  mixture,  but  the  results  were  not  economical. 

In  1789,  De  La  Metherie  proposed  to  calcine  sulphate  of 
soda  with  charcoal ;  he  thought  that  he  should  thus  obtain 
sulphurous  acid  and  carbonate  of  soda,  while  in  reality  he 
obtained  only  sulphuret  of  sodium.  This  incorrect  hypo- 
thesis, as  we  shall  see,  became  the  basis  of  the  discovery 
of  Leblanc.  As  early  as  1787,  he  had  begun  the  study  of 
this  interesting  question  ;  when  he  knew  of  the  experiments 
recommended  by  De  La  Metherie,  he  tried  them,  and  ascer- 
taining their  worthlessness,  attempted  to  modify  them. 
He  then  conceived  the  idea  of  associating  the  carbonate  of 
lime  with  the  sulphate  of  soda  and  charcoal,  when  its  success 
was  certain  and  the  magnificent  discovery  of  the  fabrication 
of  soda  was  accomplished.  Ten  months  after  the  publication 
of  De  La  Metherie,  the  problem  was  solved  by  Leblanc.  It 
was  then  that,  associated  with  the  Duke  of  Orleans,  Diz^ 
and  Shee,  he  thought  of  rendering  his  discovery  an  indus- 
trial one.  In  the  act  of  association,  and  in  a  sealed  package 
opened  in  1855,  he  described  the  process  as  he  then  under- 
stood it.  It  consisted  in  heating  in  closed  crucibles  100 
parts  of  sulphate  of  soda,  50  of  chalk,  and  25  of  charcoal.  It 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  47 


was  not  yet  the  industrial  process  as  we  know  it  at  the  present 
day.  However,  the  trials  in  the  laboratory  were  continued  ; 
a  manufactory  was  established  at  St.  Denis,  and  soon  (Sep- 
tember 23, 1791),  on  the  report  of  D'Arcet,  Desmarets,  and 
de  Servi^res,  Leblanc  obtained  a  patent  for  fifteen  years.  In 
his  description,  the  crucibles  had  disappeared;  they  were 
superseded  by  a  reverberatory  furnace;  the  proportion  of  sul- 
phate of  soda  w^as  diminished  one-half;  in  a  word,  the  real 
industrial  process  was  exposed  with  such  precision  that  since 
that  time  very  few  changes  have  been  made. 

Unhappily,  fortune  was  not  to  reward  Leblanc.  The 
manufactory  of  St.  Denis  was  just  beginning  to  work  when 
the  revolution  put  an  end  to  all  business;  the  property  of 
the  Duke  of  Orleans  was  seized,  and,  the  manufactory  being 
included,  the  fabrication  was  stopped.  Soon,  the  Continental 
war  preventing  t?ie  importation  of  Spanish  sodas,  the  French 
industry  felt  the  loss  of  this  important  element  so  essential 
to  its  work.  Then,  on  the  proposition  of  Carny,  the  com- 
mittee of  public  safety  obliged  the  inventors  of  the  process 
to  manufacture  soda  from  chloride  of  sodium,  and  to 
sacrifice  to  the  country  the  fruit  of  their  discoveries.  Le- 
blanc first  offered  his  processes  to  the  committee;  soon  a 
report  from  Lelievre,  Pelletier,  D'Arcet,  and  Giroux,  ren- 
dered them  public,  but  it  was  not  Leblanc  who  put  them 
into  practice.  The  property  of  the  Duke  of  Orleans  was  sold, 
and  the  manufactory  with  them.  However,  that  same 
manufactory  was  given  back  to  Leblanc  as  an  indemnity  for 
the  publication  of  his  process  ;  but  he  could  not  find  the 
capital  necessary  for  conducting  it,  and,  notwithstanding  all 
his  exertions,  he  utterly  failed  to  accomplish  anything,  and 
was  at  the  time  of  his  death,  in  1806,  in  a  state  of  abject 
poverty. 

However,  if  the  author  of  this  discovery  was  dead,  it  was 
not  so  with  the  discovery  itself ;  notwithstanding  the  diffi- . 
culty  of  obtaining  saltpetre  to  manufacture  sulphuric  acid, 
and  then  the  sulphate  of  soda,  the  process  of  Leblanc  was 
soon  put  in  practice  by  several  manufacturers.  It  was  first 
Payen,  then  Carny,  who  applied  it :  the  first  near  Paris,  the 


48 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES.- 


second  at  Dieuze.  The  fabrication  of  soda  was  rapidly  grow- 
ing, and  in  1806  glasses  were  seen  at  the  exposition  of  in- 
dustry, sent  by  the  manufactory  of  Saint-Gobain,  prepared 
with  artificial  soda.  However,  the  new  product  had  one 
defect  which  often  caused  it  to  be  rejected  by  the  trade;  this 
defect  consisted  in  its  sulphuretted  nature.  D'Arcet  found 
the  cause  of  that  imperfection.  Leblanc's  furnace  was  rec- 
tangular, and  the  flame  was  not  active  enough  in  the  angles, 
and  there  resulted  a  partial  transformation  of  the  sulphate 
of  soda  into  sulphuret  of  sodium.  D'Arcet  rounded  off  the 
angles,  and  transformed  the  rectangular  furnace  into  an 
elliptic  one.  With  this  improvement,  the  fabrication  of 
artificial  soda  rapidly  increased,  and  in  1812,  notwithstand- 
ing the  absolute  prohibition  of  foreign  sodas,  the  price  of 
that  substance  had  diminished  fully  two-thirds. 

Fabrication  of  Crude  Soda. — This  fabrication  comprises 
three  distinct  operations,  which  are :  1.  The  transformation 
of  the  chloride  of  sodium  (common  salt)  into  sulphate  of  soda, 
by  sulphuric  acid;  2.  The  mixture  of  the  sulphate  of  soda 
with  the  chalk  and  charcoal ;  3.  The  calcination  of  the  soda, 
or  the  conversion  of  the  sulphate  of  soda  into  carbonate,  in 
a  reverberatory  furnace. 

Sulphate  of  Soda. — The  sulphate  of  soda  manufactured  in 
France  and  England  is  destined  for  the  preparation  of  crude 
soda.  The  processes  followed  in  its  manufacture  vary  accord- 
ing to  the  localities.  When  hydrochloric  acid  has  to  be  col- 
lected, common  salt  is  decomposed  b}"  sulphuric  acid  in  cast- 
iron  cylinders,  heated  in  various  ways. 

But  at  Marseilles,  where  the  fabrication  of  artificial  soda 
constitutes  one  of  the  most  important  trades,  the  greater  part 
of  the  hydrochloric  acid  produced  during  the  operation  is 
lost.  The  sulphate  of  soda  is  directly  prepared  in  reverbera- 
tory furnaces  by  decomposing  salt  by  sulphuric  acid.  These 
furnaces  are  generally  divided  into  tw^o  compartments.  The 
part  placed  near  the  hearth  is  destined  for  the  fabrication  of 
the  crude  soda  (carbonate  of  soda);  the  second  part  is  sepa- 
rated from  the  first  by  a  low  brick  wall ;  the  side  of  this  part 
is  formed  of  hard  stone,  in  which  a  cavity  is  cut;  it  is  in 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  49 


this  cavit}^  that  the  sulphate  of  soda  is  prepared,  by  the  re- 
action of  sulphuric  acid  ou  salt.  The  proportions  of  acid 
and  salt  generall3^  used  are  : — 

Salt   2000  lbs. 

Sulphuric  acid  at  50o   3200  " 

The  salt  is  first  introduced  into  the  cavity,  then  the  sul- 
phuric acid  at  50°  is  poured  upon  it.  Under  the  influence 
of  heat  the  decomposition  takes  place ;  the  hydrochloric 
acid  resulting  from  the  reaction  is  disengaged,  and  the  sul- 
phuric acid  combines  with  the  soda  to  form  sulphate  of  soda. 

The  operation  lasts  from  three  to  four  hours.  It  is  ascer- 
tained that  it  is  finished,  when  the  mixture  has  acquired  a 
pasty  consistency,  and  when  no  more  hydrochloric  acid  is 
disengaged.  To  bleach  the  sulphate  and  disengage  the  last 
portions  of  hydrochloric  acid  it  contai)is,  the  temperature  of 
the  furnace  is  raised.  When  the  salt  is  sufiiciently  dried, 
it  is  taken  out. 

If  the  operation  has  been  well  conducted,  a  nearly  white 
sulphate  is  obtained.  Thus  prepared,  the  salt  constitutes  an 
acid  sulphate.  It  is  specially  employed  to  prepare  soft,  or 
purely  alkaline  soda. 

The  above  quantities  give  from  2200  to  2260  lbs.  of  sul- 
phate of  soda  well  prepared,  or  from  110  to  113  lbs.  of  sul- 
phate for  100  of  salt.  By  a  later  process  the  hydrochloric 
gas  forming  hydrochrotic  acid  is  saved,  thus  preventing  the 
escape  of  the  gas  which  contaminates  the  air  of  the  neigh- 
borhood. 

Mixture. — This  operation  consists  in  mixing  the  sulphate 
of  soda,  previously  calcined,  with  the  proper  proportions  of 
carbonate  of  lime  and  charcoal.  To  obtain  an  alkali  of  a 
high  degree,  it  is  essential  that  the  quantities  should  be  in 
such  proportions,  that  the  sulphate  of  soda  will  be  entirely 
transformed  into  carbonate.  Theory  indicates  the  respective 
proportions  of  the  substances  to  be  employed ;  but  in  prac- 
tice, the  doses  of  carbonate  of  lime  and  charcoal  have  to  be 
increased.  E'ot  only  is  a  more  complete  decomposition  of 
the  sulphate  of  soda  attained,  but  the  insolubility  of  the  sul- 
4 


50 


TECHNICAL  TREATISE  ON  SOAPS  AND  CANDLES. 


phuret  of  calcium  is  also  determined  by  the  formation  of  an 
oxy-sulphuret  of  that  base,  nearly  insoluble  in  cold  water; 
then  by  lixiviating  the  crude  soda  with  cold  water,  the 
solution  contains  only  the  alkali  nearly  free  from  sulphuret. 
The  best  proportions  to  use  are: — 

Calcined  sulphate  of  soda     ....      2000  lbs. 

Dry  carbonate  of  lime  2100  " 

Charcoal  1100  " 

To  render  the  reaction  more  easy,  the  substances  are  pre- 
viously ground  in  vertical  mills,  then  passed  through  a 
metallic  sieve.  The  carbonate  of  lime  must  be  perfectly 
dry  ;  generally  it  is  desiccated  by  exposing  it  for  a  few  days 
on  top  of  the  arch  of  the  furnace.  The  mixture  of  the  sub- 
stances being  intimately  effected,  the  calcination  is  proceeded 
with. 

Calcination. — As  we  have  already  said,  the  furnaces  are 
generally  made  in  two  compartments.  The  first,  where  the 
temperature  is  the  highest,  is  used  to  calcine  the  soda;  in  the 
second,  the  waste  heat  is  utilized  to  prepare  the  sulphate  of 
soda. 

When  an  operation  is  begun,  the  furnace  must  be  brought 
up  to  a  strong  red  heat  before  introducing  the  mixture. 
That  condition  being  complied  with,  introduce  the  mixture 
into  the  furnace,  and  after  spreading  it  as  evenly  as  possible, 
leave  it  exposed  for  some  time  to  the  action  of  the  heat.  In 
order  to  have  an  equal  and  regular  heat,  the  fire  requires 
great  attention,  especially  at  the  beginning  of  the  operation. 

When  the  reaction  begins,  the  mixture  softens  and  agglu- 
tinates, and  the  parts  exposed  to  the  highest  temperature 
begin  to  melt.  At  that  moment,  stir  the  mixture  with  an 
iron  rod  so  as  to  hasten  the  decomposition  of  the  sulphate. 

From  this  time,  feed  the  furnace  with*  fresh  fuel  so  as  to 
obtain  a  bright  and  continued  fire.  Continue  to  stir  the 
mixture  from  time  to  time.  It  is  ascertained  that  the  opera- 
tion is  almost  finished  when  the  fusion  is  nearly  complete, 
and  when  the  incandescent  substance  throws  out  luminous 
jets,  which  burn  with  a  white  or  bluish  flame.    These  jets, 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  51 


are  due  to  the  combastion  of  the  oxide  of  carbon  ;  when  they 
become  more  rare  and  less  intense,  it  is  a  characteristic  sign 
of  the  conversion  of  the  sulphate  of  soda  into  carbonate. 

Then  slacken  the  action  of  the  fire,  for  a  higher  elevation 
of  temperature  would  cause  the  volatilization  of  an  appreci- 
able quantity  of  soda. 

Thus,  when  the  luminous  jets  have  diminished  in  intensity, 
draw^  off  from  the  furnace  the  melted  mass,  which  is  received 
in  square  sheet-iron  boxes  five  or  six  inches  deep  and  three 
feet  in  diameter.  These  boxes  are  phiced  on  rails  and  then 
put  under  sheds.  After  the  soda  is  solidified  and  cooled,  it 
is  broken  into  large  pieces  and  put  into  barrels. 

This  soda  is  generally  in  a  melted  and  compact  mass,  par- 
ticularly if  the  calcination  has  been  pushed  too  far ;  but 
when  the  operation  has  been  well  conducted,  its  texture  is 
not  so  compact,  and  sometimes  is  porous.  It  is  preferred  in 
this  state,  because  by  lixiviation  it  is  more  easy  to  deprive  it 
of  its  soluble  salts.  When  well  prepared  it  resembles  good 
Spanish  soda ;  it  has  a  gray-ash  color,  and  is  without  smell. 
Its  richness  in  pure  alkali  is  generally  constant,  and  depends 
essentially  on  the  purity  of  the  sulphate.  If  the  sulphate 
contains  only  a  few  hundreths  of  undecomposed  salt,  and  is 
completely  converted  into  carbonate  by  proper  proportions 
of  chalk  and  charcoal,  a  soda  is  obtained  which  generally 
contains  thirty-six  per  cent,  of  alkali.  This  soda,  designated 
by  the  name  of  soft  soda,  or  alkaline  soda,  is  specially  used 
for  the  saponification  of  oils  in  the  fabrication  of  marbled 
and  white  soaps. 

As  soon  as  the  furnace  is  empty,  load  it  again  as  at  first 
w\th  a  mixture  of  sulphate  of  soda,  chalk,  and  charcoal,  and 
operate  as  we  have  indicated. 

The  complicated  reactions  are  thus  explained  :  Under  the 
influence  of  the  charcoal,  the  sul[)hate  of  soda  is  transformed 
into  sulphuret,  and  at  the  same  time,  oxide  of  carbon  is  dis- 
engaged. Afterwards,  the  sulphuret  of  sodium  and  the  car- 
bonate of  lime  are  mutually  decomposed,  and  from  that 
decomposition  result  sulphuret  of  calcium  and  carbonate  of 
soda ;  but  as  this  reaction  takes  place  at  a  temperature  at 


52 


TECHNICAL  TREATISE  ON  SOAPS  AND  CANDLES. 


which  the  carbonate  of  lime  is  decomposed,  a  part  of  the 
soda  is  obtained  in  a  caustic  state.  The  proportion  of  caustic 
soda  contained  in  the  carbonate  of  soda,  is  as  much  more 
considerable  as  the  dose  of  charcoal  has  been  increased,  and 
that  the  mixture  has  been  carried  to  a  higher  temperature. 
In  a  subsequent  chapter  we  shall  give  the  process  for  analyz- 
ing caustic  alkalies. 

We  think  it  Avill  interest  the  reader  to  know  the  real  cost 
of  the  substances  used  and  produced,  and  we  give  below  a 
detailed  table  of  the  expense  of  manufacturing  20,000  lbs.  of 
artificial  soda  in  France.  These  numbers  are  very  exact,  and 
deserve  full  confidence. 


Baw  Materials. 

Sulphate  of  soda,  14,000  lbs.  at  $1.60  the  100  lbs.        .       .       .  $224  00 

Carbonate  of  hme  in  powder,  14,700  lbs.  at  6  cents  the  100  lbs.  .  8  82 
Powdered  coal  to  transform  the  sulphate  into  carbonate,  7000  lbs. 

at  22  cents  the  100  lbs   15  40 

Coal  used  as  a  combustible  about  3  tons   16  00 

Other  Expenses. 

Labor  about  6  days   5  00 

General  expenses    6  00 


Total  1375  23 


Production. — 20,000  lbs.  of  crude  soda  marking  36  alkali- 
metric  degrees. 

We  see  by  the  above  table  that  the  expense  of  manufactur- 
ing 20,000  lbs.  of  crude  soda  is  $275.22,  which  puts  the  price 
of  100  lbs.  at  $1.38. 

Artificial  Salted  aS'oc?^.— Artificial  salted  soda  is  a  mixture 
of  soft  soda  and  common  salt.  The  proportion  of  salt  varies 
from  25  to  40  per  cent,  of  the  weight  of  the  soda. 

The  use  of  this  soda  is  necessary  for  the  coction  of  marbled 
soaps.  On  account  of  the  large  proportion  of  salt  it  contains, 
it  has  the  property  of  contracting  the  paste  of  the  soap,  and 
preventing  its  dissolution  in  the  lye.  Like  soft  artificial 
soda,  it  is  prepared  by  the  decomposition  of  the  sulphate  of 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  53 


soda  by  chalk  and  charcoal,  only  in  the  preparation  of  the 
sulphate,  the  quantity  of  sulphuric  acid  necessary  to  decom- 
pose the  salt  is  diminished,  so  that  the  sulphate  obtained 
contains  from  30  to  40  per  cent,  of  undecomposed  salt.  The 
proportions  generally  employed  are  : — 

Salt   2000  lbs. 

Sulphuric  acid  50°,  from  .       .       .       1200  to  1400  lbs. 

The  decomposition  is  conducted  in  the  same  manner  as  for 
the  soft  soda.  The  sulphate  obtained  is  calcined  and  mixed 
with  the  carbonate  of  lime  and  coal  in  the  following  propor- 
tions:— 

Sulphate  of  soda 
Carbonate  of  lime 
Coal  in  powder 

The  substances  are  reduced  to  powder,  and  intimately 
mixed  together.  The  decomposition  takes  place  in  the  same 
manner  as  for  the  soft  soda. 

Salted  artificial  soda  has  a  less  constant  composition  than 
soft  soda.  Independently  of  the  strong  proportion  of  salt  it 
contains,  it  is  also  more  sulphuretted  than  the  latter.  This 
inconvenience  is  due  to  a  more  or  less  considerable  portion 
of  sulphuret  of  sodium,  which  has  not  been  decomposed  dur- 
ing the  reaction,  and  is  left  mixed  with  th«  soda.  This 
inconvenience  may  easily  be  remedied  by  completely  trans- 
forming all  the  sulphuret  into  carbonate,  by  introducing  an 
excess  of  chalk  into  the  mixture.  Thus,  an  oxi-sulphuret  of 
calcium,  very  slightly  soluble  in  cold  water,  is  obtained,  and 
by  lixiviating  the  soda  with  cold  water,  a  solution  is  ob- 
tained, which  only  contains  traces  of  the  sulphuret. 

It  is  evident,  that  under  many  circumstances  the  sulphuret 
might  be  troublesome,  and  such  would  be  the  case,  if  this 
soda  were  used  in  the  fabrication  and  purification  of  fine 
soaps.  But  we  must  remark,  that  artificial  salted  soda  is 
particularly  employed  in  the  fabrication  of  marbled  soaps, 
and  besides  its  advantage  of  contracting  the  paste  of  the  , 
soap,  the  sulphuret  it  contains  contributes  to  develop  the 
beauty  and  intensity  of  the  marbling. 


2000  lbs. 
1300  " 
9000  " 


54  TECHNICAL  TREATISE  ON  SOAPS  AND  CANDLES. 


Chemical  analysis  demonstrates  that  100  parts  of  crude 
artificial  soda  contain  on  an  average : — 


The  insoluble  residuum  is  composed  of  oxysulphuret  of 
lime,  and  coal. 

Bejined  Carbonate  of  Soda. — Purified  carbonate  of  soda  is 
designated  ih  the  trade  by  the  name  of  soda  ash.  This  salt 
is  very  important  on  account  of  its  numerous  applications  in 
industry.  It  is  specially  used  in  the  preparation  of  toilet 
soaps.  For  their  fabrication  the  richest  in  alkali  is  preferred, 
and  principally  the  one  which  is  entirely  free  from  sulphuret. 

For  a  long  time  this  salt  was  obtained  by  the  lixiviation 
of  the  ashes  of  sea-weeds,  but  now  it  is  extracted  from  arti- 
ficial crude  soda. 

To  prepare  this  salt,  select  the  soda  which  is  richest  in 
alkali,  and  containing  the  least  sulphuret.  The  lixiviation 
may  be  ettected  by  various  processes.  In  the  manufacture 
of  crude  soda,  where  sal  soda  is  also  prepared,  the  pro- 
cess is  rational,  simple,  and  economical.  Baskets  made  of 
metallic  cloth  are  filled  with  coarsely  powdered  soda,  and 
then  successively  passed  through  solutions  of  soda  growing 
weaker  and  weaker.  The  last  passage  is  through  pure  water. 
By  this  operation  a  solution  at  25°  or  28°  B.  is  obtained. 
To  have  it  perfectly  limpid,  it  is  left  to  settle  for  several 
days,  and  is  then  concentrated. 

This  operation  is  generally  conducted  in  four  cast-iron 
kettles  arranged  in  steps,  and  heated  by  the  same  hearth. 
The  first  receives  the  heat  directly  all  over  its  surface ;  the 
flame  afterwards  heats  the  others,  and  then  is  lost  in  the 
chimney.  The  top  kettle  is  employed  to  boil  the  solutions, 
the  middle  ones  to  evaporate  them,  and  the  lower  one  to 
concentrate  them  to  dryness.  During  the  operation,  add  new 
solutions  to  take  the  place  of  the  evaporated  water,  in  such  a 
manner  that  the  level  of  the  liquors  is  always  the  same.  To 
prevent  the  salt  from  attaching  itself  to  the  bottom  and  the 


Pure  soda 
Salt  . 


20  to  25 
30  to  35 
2  to  5 
1  to  2 


Undecomposed  sulphate  of  soda 
Foreign  salts      .       .  . 


MATERIALS  USED  IN  THE  MANUFACTURE  OP  SOAPS  55 


sides  of  the  first  kettle,  take  it  out  with  a  skimmer  as  fast  as 
it  deposits,  and  let  it  drain  on  an  inclined  plane,  or  on 
shelves  lined  with  lead.  Continue  this  until  all  the  solutions 
are  evaporated  to  dryness. 

To  obtain  a  very  pure  and  very  rich  carbonate  of  soda, 
some  manufacturers  evaporate  the  solution  until  a  pellicle  is 
formed  on  the  surface,  and  in  this  state  pour  it  into  sheet- 
iron  vats,  where  it  crystallizes.  A  few  days  after,  the 
mother-liquor  is  decanted,  and  the  salt  is  left  to  drain.  The 
crj^stals  contain  only  a  few  hundreths  of  foreign  salts;  the 
mother-liquor  contains  uncrystallizable  caustic  soda,  sulphate 
of  soda,  and  chloride  of  sodium.  Whatever  be  the  method 
of  operating,  the  salt  of  soda  obtained  always  contains  a 
large  amount  of  water,  interposed  between  its  crystals.  Be- 
sides, it  is  colored  by  organic  substances,  which  give  it  a 
brownish  shade. 

To  obtain  this  salt  very  dry  and  very  white,  calcine  it  in 
a  reverberatory  furnace,  strongly  heated.  Furnaces  in  which 
the  calcination  takes  place  have  their  beds  entirely  covered 
w^ith  a  thick  and  half-melted  coat  of  salt  itself ;  the  bricks 
or  stones  being  rapidl}^  destroyed  under  the  influence  of  a 
high  temperature.  The  carbonate  of  soda  thus  obtained  is 
very  white,  and  is  much  richer  in  pure  soda  when  the  crude 
soda,  from  which  it  is  exhausted,  is  itself  pure. 

The  sal  soda  is  obtained  nearly  chemically  pure,  as  we 
have  said,  by  concentrating  the  solutions  of  crude  soda  and 
causing  them  to  crystallize.  The  crystals  being  drained 
and  calcined  in  a  reverberatory  furnace,  yield  a  carbonate  of 
soda  of  90  or  92  alkalimetric  degrees. 

The  amount  of  refi.ned  soda  ash  from  crude  soda,  varies 
according  to  the  quality  of  the  soda  used.  Generally,  1000 
pounds  of  good  crude  soda,  at  36°,  yield  from  380  to  400 
pounds  of  a  very  white  refi.ned  soda  ash,  and  marking  from 
80  to  85  alkalimetric  degrees. 

Crystallized  Carbonate  of  Soda  or  Crystals  of  Soda. — Crj^stals 
of  soda  constitute  the  pure  subcarbonate  of  soda.  Although 
less  used  than  the  dry  carbonate  of  soda,  this  salt  finds  nu- 


56 


TECHNICAL  TREATISE  ON  SOAPS  AND  CANDLES. 


merous  applications  in  the  arts.  In  soap  factories  it  is  used 
to  prepare  the  pure  Ije  of  soda. 

!N"early  all  the  crystallized  sal  soda  found  in  commerce  is 
obtained  by  the  lixiviation  of  artificial  soda.  To  prepare  it 
use  the  purest  and  richest  soda.  The  crude  soda  is  lixivi- 
ated in  the  same  manner  as  we  have  indicated  above.  All 
the  solutions  which  mark  from  20°  to  25°  B.,  are  mixed 
in  large  sheet-iron  vats  and  allowed  to  rest ;  a  few  days  after, 
when  all  the  liquors  are  clear,  they  are  decanted  and  sub- 
mitted to  a  gentle  ebullition  in  a  cast-iron  kettle. 

When  the  boiling  solutions  mark  from  28°  to  30°,  they 
are  poured  back  into  the  vats,  which  are  surrounded  with 
coarse  cloths,  so  as  to  retard  the  cooling.  By  resting,  a  sedi- 
ment is  deposited  at  the  bottom  of  the  kettles,  and  the  liquor 
becomes  perfectly  limpid.  When  the  temperature  is  at  70° 
to  75°  C.  (158°  to  167°  F.),  the  liquors  are  decanted  and  then 
set  to  crystallize,  either  in  earthen  jars,  or  in  small  sheet- 
iron  vats  of  a  capacity  of  6  or  8  gallons. 

In  winter,  the  crystallization  takes  place  in  the  space  of  a 
few  days.  When  the  concentration  of  the  lyes  has  been 
carried  to  34°  or  35°  B.,  the  crystallization  is  so  complete 
that  very  little  mother-liquor  is  left.  The  concentrated  lyes 
at  28°  to  30°,  give  less  crystals,  but  the  product  is  richer. 
The  caustic  soda  and  the  foreign  salts  remain  in  solution  in 
the  mother-liquor,  while  in  the  first  case,  they  crystallize 
with  the  carbonate  of  soda. 

Another  process  is  also  used  to  prepare  the  crystals  of  soda. 
It  consists  in  dissolving  retined  soda  ash,  of  a  high  degree,  in 
boiling  water.  The  operation  is  effected  in  a  cast-iron  kettle. 
When  the  liquor  marks  30°  B.,  yg^'oxF  quicklime,  diluted 
with  water,  is  added  to  it.  After  an  ebullition  of  a  few 
minutes  the  fire  is  removed,  and  the  liquor  is  allowed  to 
rest,  so  as  to  become  limpid.  This  result  being  obtained, 
the  clear  liquid  is  drawn  off  and  left  to  crystallize.  The 
crystallization  takes  place  in  a  few  days ;  the  salt  is  then 
separated  from  the  mother-liquor  and  allowed  to  drain. 
This  process  yields  whiter,  finer,  and  purer  crystals  than 
those  obtained  by  the  direct  treatment  of  the  crude  soda. 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  57 


The  first  process,  however,  is  generally  used  because  the 
crystallized  carbonate  of  soda  can  be  extracted  from  the 
crude  lyes,  while,  by  the  second,  it  is  necessary  to  employ 
the  refined  salt  of  soda. 

The  mother-liquor  from  the  first  crystallization  yields  after 
a  strong  concentration  at  34°  B.  a  new  quantity  of  crystals 
of  soda,  which  can  be  purified  by  dissolving  it  in  half  its 
weight  of  boiling  water.  The  uncrystallizable  mother-liquor 
is  used  to  prepare  a  caustic  salt  of  soda  of  a  weak  degree. 
This  salt  contains  only  from  40  to  50  per  cent,  of  pure  soda. 

Crystallized  carbonate  of  soda  contains  62.80  per  cent,  of 
water,  so  that  100  pounds  represent  only  37.20  of  dry  carbon- 
ate. This  salt  is  very  soluble  in  water.  Boiling  water  dis- 
solves almost  its  own  weight,  and  cold  water  almost  half.  In 
the  arts,  the  great  solubility  of  this  salt  is  utilized  to  purify 
it ;  for  this  purpose  it  is  dissolved  in  the  least  possible  quan- 
tity of  boiling  water.  The  liquor  is  left  to  crystallize,  and 
it  deposits,  by  cooling,  fine  crystals  of  pure  carbonate  of  soda. 

This  salt  is  thus  formed  : — 

Carbonic  acid  15.42 

Soda  21.78 

Water  62.80 

100.00 

Caustic  Salts  of  Soda. — The  caustic  salts  of  soda  represent 
for  the  same  weight,  a  larger  quantity  of  pure  soda  than  the 
same  salts  when  carbonated.  Starting  from  this  principle, 
there  is  an  advantage  in  using  salts  of  soda,  the  carbonic 
acid  of  which  has  been  partly  or  totally  eliminated,  for  the 
ponderal  quantity  of  the  missing  acid  is  substituted  by  an 
equivalent  weight  of  pure  soda.  It  is  thus  that  in  their  dif- 
erent  applications  of  industry,  caustic  alkalies  produce,  at 
equal  weights,  more  considerable  results  than  when  in  the 
state  of  carbonates. 

The  fabrication  of  the  caustic  salts  of  soda  is  very  simple. 
For  this  purpose  it  is  sufiicient  to  mix  the  crude  soda  with 
30  per  cent,  of  powdered  lime  (hydrated  lime),  and  proceed 


58  TECHNICAL  TREATISE  ON  SOAPS  AND  CANDLES. 


with  the  lixiviation  in  the  same  manner  as  in  the  prepara- 
tion of  the  salt  of  soda. 

The  result  of  the  washing  gives  lyes  marking  about  25°  B. 
These  lyes,  being  clarified  by  settling,  are  rapidly  evaporated 
to  dryness  in  cast-iron  kettles.  The  salt  is  drained  and 
carried  into  a  reverheratory  furnace,  where  it  is  spread  in  a 
layer  from  three  to  four  inches  thick. 

The  furnace  is  at  first  heated  moderately  to  dry  the  salt 
slowly  without  melting  it,  then  the  temperature  is  raised 
until  it  becomes  red.  This  is  an  essential  condition  to  expel 
the  water,  and  destroy  the  organic  matters,  which  color  it. 
During  the  operation  the  mass  is  stirred,  so  as  to  multiply 
the  points  of  contact  of  the  substance  with  the  caloric.  The 
product  thus  obtained  is  white,  and  excessively  caustic.  Ex- 
posed to  the  air  it  absorbs  carbonic  acid,  and  passes  to  the 
state  of  carbonate. 

Salts  of  soda,  more  or  less  caustic,  are  also  found  in  the 
trade.  They  are  prepared  with  the  mother-liquors  from  the 
fabrication  of  the  crystals  of  soda.  These  liquors  contain  in 
solution,  large  proportions  of  caustic  soda  mixed  with  dif- 
ferent salts  principally  with  sulphates  and  chlorides.  By 
concentrating  them  to  dryness,  and  incinerating  the  residu- 
um, a  kind  of  caustic  salt  of  soda  is  obtained. 

From  these  remarks  it  may  be  seen  that  owing  to  the 
facility  of  obtaining  the  artificial  caustic  soda  which  is  now 
made  ready  for  use  and  in  a  very  nearly  pure  state,  and 
that  almost  all  manufacturers  of  soap  are  at  present  using  it 
in  their  works,  most  of  the  caustic  soda  of  commerce  will 
bear  analysis  for  its  percentage  of  sodium  hydrate.  We 
give  the  analysis  of  an  English  caustic  soda,  branded  70°, 
which  we  have  tested. 

Sodium  hydrate   83.840 


Alumiaum 


chlorate 
chloride 
sulphite 
sulphate 
silicate 


4.686 
6.522 
4.503 
0.039 
0.470 
trace 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  59 


This  shows  at  a  glance  that  the  caustic  soda  made  for  the 
manufacture  of  soap  is  reasonably  pure — this  sample  show- 
ing no  trace  of  carbonate  of  soda,  the  other  salts  not  being  in 
sufficient  quantity  to  impair  the  soap,  which  if  boiled  would 
almost  entirely  precipitate  with  the  waste  lye.  The  healthy 
rivalry  of  the  manufacturers  of  soda  is  such  that  an  impure 
article  could  scarcely  find  a  market.  These  sodas  possess 
many  advantages  to  the  soap-maker  in  these  days  over  those 
formerly  in  use,  and  a  saving  of  much  time  and  labor  that 
had  to  be  spent  in  making  caustic  the  sodas  of  commerce, 
which  were  of  such  varying  qualities  and  strengths,  and  filled 
with  so  many  foreign  salts,  that  it  required  an  expert  chemist 
to  anally ze  them.  At  present,  when  we  know  the  relative 
purity  or  strength  of  a  certain  make  of  soda,  and  by  test 
ascertain  the  amount  of  caustic  soda  it  contains,  the  hydro- 
meter of  Baume  will  give  us  the  specific  gravity,  and  we  can 
easily  judge  of  the  quantity  necessary  to  use. 

The  following  table  may  prove  useful  in  this  connection. 


Specific  gravity. 

Per  cent. 

Specific  gravity. 

Per  ceut. 

2.00 

77.8 

1.40 

29.0 

1.85 

63.6 

1.36 

26.0 

1.72 

53.8 

1.32 

23.0 

1.63 

46.6 

1.29 

19.0 

1.56 

41.2 

1.23 

16.0 

1.50 

36.8 

1.18 

13.0 

1.47 

34.0 

1.12 

9.0 

1.44 

31.0 

1.06 

4.7 

It  is  almost  needless  to  explain  that  the  specific  gravity  of 
the  solution  increases  with  the  amount  of  caustic  soda  dis- 
solved in  it.  In  another  section  we  w^ill  give  the  necessary 
working  tables  for  manipulation. 

On  the  score  of  economy  in  the  cost  of  soap-maker's  lye, 
there  might  be  conditions  where  the  barilla,  kemp,  and  other 
soda  ashes  could  be  economically  used,  but  they  can  hardly 
apply  to  this  country,  unless  it  be  in  the  far  West,  where 
many  natural  sources  of  soda  are  found,  and  where  there  are 
several  soda  works  already  established,  and  whose  products 
rival  the  English. 


60  TECHNICAL  TREATISE  ON  SOAPS  AND  CANDLES. 


Caustic  Soda  from  Cryolite. 

From  cryolite,  a  mineral  found  in  Greenland,  a  caustic 
soda  is  now  made  in  this  country,  Germany,  and  Denmark, 
which  is  nearly  free  from  impurities.  Cryolite  is  the  fluoride 
of  aluminum  and  soda,  and  in  preparing  the  soda,  the  sodium 
aluminate  is  dissolved  out  with  water,  and  decomposed  with 
carbonic  acid,  the  hydrate  of  alumina  being  separated,  and 
formed  into  an  alum  useful  in  the  arts.  The  remaining  car- 
bonate of  soda  is  dissolved  and  condensed  to  form  crystal- 
lized carbonate  of  soda,  or  it  is  decomposed  with  lime  to 
form  caustic  soda,  in  the  manner  already  described.  The 
sodas  from  this  source  are  so  nearly  pure  that  they  claim  a 
preference  in  the  manufacture  of  most  soaps,  particularly 
those  made  by  the  cold  or  extempore  process  when  all  the 
impurities  the  alkalies  may  contain  remain  in  the  soap. 
Cryolite  is  also  the  most  convenient  source  of  aluminum,  a 
valuable  silver-like  metal. 

Ammonia.    Amynoniaque,  Fr.    Ammoniak,  Ger.  Volatile 

alkali. 

This  important  alkali  deserves  mention  here,  but  has  few 
properties  applicable  to  our  art,  unless  in  an  analytical  test  in 
some  experiments,  when  it  can  be  recommended  as  a  normal 
alkali  free  from  impurities.  For  soap  it  has  no  practical  use, 
though  we  find  several  patents  have  been  given  for  its  addi- 
tion to  other  soap  where  it  is  claimed  to  improve  its  detersive 
action.  It  has  many  uses  in  pharmacy  and  the  arts,  but  they 
are  foreign  to  the  subject  of  our  work. 

RUBINIUM  AND  CaESIUM 

are  alkalies  recently  discovered  which  are  analogous  to 
potash  in  their  character,  but  have  no  application  in  the  art 
of  making  soap,  as  they  are  scarce  and  expensive. 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  61 


Lime.    Chaux,  Fr.    Kalk^  Ger. 

Lime,  called  quicklime  and  caustic  lime,  is, chemically,  cal- 
cium oxide,  and  does  not  occur  naturally,  but  always  with  an 
acid  oxide,  as  carbonate,  sulphate,  silicate,  etc.  The  use  of 
lime  to  the  soap-maker  is  important,  for  by  its  power  of  ex- 
tracting the  carbonic  acid  from  alkalies,  they  are  thereby 
made  caustic  and  suitable  for  combining  with  the  fatty  acids 
and  forming  soap,  though  it  does  not  form  a  component  part 
of  it.  A  soap  can  be  made  of  lime  and  a  sebasic  acid,  but  it 
is  insoluble. 

Lime  used  for  technical  purposes  is  prepared  by  calcining 
natural  carbonate  of  lime  in  kihis.  During  the  burning  the 
carbonic  acid  is  disengaged,  and  quicklime  is  the  product  of 
the  calcination. 

The  qualities  of  lime  essentially  depend  on  the  purity  of 
the  carbonate  used  to  prepare  it.  When  the  calcareous  stone 
(carbonate  of  lime)  is  mixed  with  large  proportions  of  quartz, 
magnesia,  or  alumina,  a  lime  of  an  inferior  quality  is  ob- 
tained, which  slacks  with  difficulty,  and  forms,  with  water, 
a  paste  without  homogeneity.  It  is  then  called  poor,  and  is 
rarely  used  in  soap-making.  Lime  prepared  with  a  carbon- 
ate sensibly  pure,  that  is,  which  contains  only  traces  of 
foreign  matters,  is  of  a  superior  quality,  and  is  called /a^.  It 
rapidly  combines  with  water,  and  grows  very  warm.  If  very 
little  water  is  added,  it  slacks  and  forms  a  white  and  light 
powder,  with  a  burning  and  caustic  taste,  and  turning  the 
blue  vegetable  colors  green.  Lime  thus  prepared  is  known 
by  two  difterent  names.  For  the  chemist  it  is  hydrated  lime, 
for  the  manufacturer  it  is  slacked  lime. 

If  a  sufficient  quantity  of  water  is  poured  on  slacked  lime, 
it  combines  with  that  liquid.  The  elevation  of  temperature, 
which  takes  place  during  the  combination,  often  reaches 
350°  C.  (662^^  F.).  If  the  quantity  of  water  is  large  enough, 
a  more  or  less  thin  paste  is  obtained,  which  is  called  milk  of 
lime.  It  is  always  in  this  form  that  lime  is  used  to  prepare 
caustic  lyes  of  potash  or  soda. 


62  TECHNICAL  TREATISE  ON  SOAPS  AND  CANDLES. 


Lime  recently  burned  is  white,  or  slightly  colored,  if  the 
limestone  used  to  prepare  it  contains  oxide  of  iron.  To  as- 
certain if  it  is  completely  caustic,  treat  a  few  drachms  by 
nitric  acid.  If  the  lime  is  entirely  caustic,  it  ought  to  dissolve 
in  the  acid  without  disengaging  carbonic  acid.  If  there  is 
any  effervescence  during  the  solution,  it  is  a  proof  that  it 
still  contains  carbonate  of  lime,  which  has  not  been  trans- 
formed into  caustic  lime.  Entirely  caustic  lime  is  more  de- 
sirable, as  it  decomposes  the  carbonates  of  potash  and  soda 
better. 

Its  density  is  not  constant,  it  varies  according  to  the  nature 
and  purity  of  the  carbonates  which  have  produced  it.  Its 
mean  specific  gravity  is  2.4. 

Quicklime  exposed  for  some  time  in  the  air,  attracts  its 
water  and  carbonic  acid :  it  is  transformed  into  carbonate  of 
lime.  In  this  state  it  has  lost  all  its  causticity,  and  does  not 
possess  the  property  of  depriving  the  carbonates  of  potash 
and  soda  of  their  carbonic  acid. 

Water  will  dissolve  a  certain  proportion  of  lime.  Very 
exact  and  recent  experiments  have  shown  that  one  thousand 
parts  of  water  dissolve  one  of  quicklime.  That  small  quan- 
tity is,  however,  sufficient  to  communicate  to  water  a  strong 
alkaline  reaction,  and  restore  the  blue  of  litmus  paper,  red- 
dened by  an  acid. 

Lime-water  is  a  valuable  reagent  for  ascertaining  the  causti- 
city of  lyes  of  potash  and  soda.  Pour  a  small  quantity  of 
the  lye  to  be  tested  into  a  glass,  and  add  to  it  perfectly  lim- 
pid lime-water  ;  if  the  lye  is  completely  caustic,  the  two 
liquors  remain  limpid  ;  if,  on  the  contrary,  there  is  in  the  lye 
a  portion  of  undecomposed  alkaline  carbonate,  a  white  pre- 
cipitate of  carbonate  of  lime  is  produced. 

Lime  plays  an  important  part  in  the  preparation  of  lyes. 
It  is  the  essential  and  indispensable  agent  of  their  causticity. 
When  we  examine  the  preparation  of  lyes,  we  shall  indicate 
the  special  conditions  of  this  operation,  one  of  the  most  im- 
portant in  its  manufacture;  We  may  here  state  that  lime  is 
not  an  integral  part  of  soap — its  action  being  chemical.  It 
'jombines  with  the  carbonic  acid  of  the  alkaline  carbonate 


MATERIALS  USED  IN  THE  MA*NUFACTURE  OF  SOAPS.  63 


with  which  it  is  in  contact,  and  forms  an  insoluble  carbonate 
of  lime.  The  pure  alkali,  or  hydrated  alkali,  remains  in  solu- 
tion in  the  water,  and  constitutes  the  caustic  lye  used  in  the 
fabrication  of  soaps. 

We  may  add,  that  lime  used  to  prepare  lyes  must  always 
be  of  good  quality,  and,  if  possible,  recently  burned.  It  ought 
to  mix  easily  with  Avater,  and  should  not  effervesce  with 
acids.  In  places  where  it  is  difficult  to  obtain  it  readily,  it 
ought  to  be  kept  in  barrels  perfectly  closed,  and  in  a  dry 
place,  because  by  being  exposed  to  the  air  it  attracts  moist- 
ure and  carbonic  acid.  But  when  lime-kilns  are  near  a 
manufactory  of  soap,  it  is  better  to  use  lime  recently  burned. 

When  the  lime  is  supposed  to  contain  impurities  it  would 
be  advisable  to  submit  it  to  the  alkalimetric  test,  for  this  pur- 
pose. Besides  titered  nitric  acid  a  solution  of  sal-ammonia  is 
needed,  which  in  one  hundred  parts,  contains  about  twenty- 
five  parts  of  sal-ammonia.  For  this  test  weigh  off  exactly  2.8 
grammes  (43.20  grains)  of  burned  lime,  place  it  in  the  100  cubic 
centimetre  (3.38  flu.  ozs.)  trial  glass,  add  at  first  some  water, 
so  that  the  lime  be  slacked  and  reduced  to  powder  ;  then 
again  40  cubic  centimetres  of  water  (1.35  fiu.  ozs.),  25  cubic 
centimetres  (0.845  flu.  oz.)  of  the  sal-ammonia  solution,  and 
finally  fill  up  to  the  mark  with  water,  until  in  all  100  cubic 
centimetres  (3.38  flu.  ozs  )  are  obtained,  l^ow  place  a  tightly 
fitting  cork  in  it,  shake  repeatedly,  and  allow  the  whole  to  clear 
oft',  by  settling.  Then  take  10  cubic  centimetres  (0.338  flu.  oz.) 
of  the  liquid  into  a  beaker,  which  contains  already  10  or  20 
cubic  centimetres  (0.338  or  0.676  flu.  oz.)  distilled  water,  color 
with  tincture  of  litmus  blue,  and  admit  by  means  of  a  grad- 
uated pipette  the  normal  nitric  acid,  until  the  blue  color 
changes  into  that  of  a  red  onion.  The  cubic  centimetres  of 
nitric  acid  used,  multiplied  by  ten,  give  the  percentage  of 
caustic  lime  which  the  tested  lime  contains. 

A  very  good  mode  for  keeping  lime  for  use  is  to  slack  it 
into  a  stirt' paste  and  put  it  into  water-tight  vats  or  barrels 
where  it  will  keep  a  long  time,  while  only  the  upper  surface 
having  absorbed  carbonic  acid  can  be  removed  before  using 
for  causticizing  the  lye. 


64 


TECHNICAL  TREATISE  ON  SOAPS  AND  CANDLES. 


Water.    Eau^  Fr.    Wasser^  Ger. 

Water  in  the  manufacture  of  soap  performs  a  prominent 
and  indispensable  part, and  may  well  be  called  a  raw  material. 
It  is  particularly  important  to  have  it  pure,  both  for  the  soap 
and  as  an  ingredient  for  the  lye.  There  are  often  dissolved 
in  the  water  of  wells  and  springs  various  earthy  salts,  lime, 
dolomite,  etc.  These  salts  often  decompose  a  portion  of  the 
soap,  and  when  used  in  making  or  melting  they  also  cause  a 
loss  in  the  causticity  of  the  lye,  which  in  a  large  factory  re- 
sults in  a  great  pecuniary  loss. 

Thus  it  is  exceedingly  important  to  see  that  the  water 
used  is  entirely  pure,  and  if  that  is  not  possible,  to  ascertain 
the  extent  and  kind  of  impurities,  and  to  iind  a  suitable 
remedy  to  make  the  water  fit  for  use.  To  give  exact  instruc- 
tions for  the  analysis  of  all  waters  would  require  much  space 
which  is  not  possible  here.  Yet,  as  it  is  important  we  will 
give  the  test  recommended  by  Fleck,  which  not  only  offers 
the  most  reliable  but  furnishes  the  most  ample  and  accurate 
results  for  the  technic,  and  besides  all  this,  is  very  feasible. 
It  rests  upon  the  decomposition  of  the  earthy  salts  which 
are  present  in  the  water,  by  means  of  a  soap  solution  of  a 
certain  degree.  To  ascertain  the  final  reaction  of  the  water 
to  be  tested,  it  is  only  necessary  to  color  the  same  with  an 
always  equal  amount  of  reddish  litmus  tincture  until  it  be- 
comes light  red.  As  soon  as  all  the  earthy  salts  are  decom- 
posed by  the  soap,  the  liquid  takes  with  a  new  addition  of 
soap  solution,  a  drop  at  a  time,  its  former  bluish  color.  The 
soap  solution  is  so  normal,  that  20  cubic  centimetres  (0.676 
flu.  oz.)  of  it  in  100  cubic  centimetres  (3.38  flu.  ozs.)  of  a 
saturated  solution  of  gypsum,  become  decomposed.  By  this 
the  degree  of  hardness  of  a  water  is  determined ;  as  also  in 
the  case  of  a  water,  of  which  100  cubic  centimetres  (3.38  flu. 
ozs.)  require  20  cubic  centimetres  (0.676  flu.  oz.)  soap-solu- 
tion, and  is  noted  as  20;  in  other  words,  the  cubic  centi- 
metre of  soap  solution  used,  expresses  the  immediate  degree 
of  hardness  of  the  water  tested. 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  65 


The  main  requisite  for  these  tests  is  an  entirely  neutral 
soap  ;  which  must  contain  neither  free  nor  carbonated  alkali. 
The  common  soaps  being  for  this  purpose  seldom  applicable, 
Marseilles  soap,  therefore,  as  a  rule,  is  used  for  this  purpose. 
In  the  absence  of  this  soap,  a  neutral  soap  can  easily  be 
made,  by  dissolving  a  common  oil  or  tallow-soap  in  dis- 
tilled water,  and  settling  it  with  warm  culinary  salt,  and 
by  washing  out  the  grainy  soap  with  a  gradually  diluted 
culinary  salt  solution  upon  a  filter,  till  the  liquid  indicates 
but  a  weak  alkaline  reaction.  Finally,  the  yet  moist  soap 
is  pressed  in  linen,  in  order  to  remove  the  still  adhering 
parts  of  the  solution  of  culinary  salt.  After  drying  it 
somewhat  in  the  air,  it  is  dissolved  by  warming  with 
about  ten  times  its  volume  of  70°  or  80°  alcohol,  allowing 
it  to  cool  off,  settle,  and  then  filter.  Stronger  alcohol  must 
not  be  used,  because  the  solution  would  congeal.  To  cause 
this  soap  solution  to  decompose  20  cubic  centimetres  (0.676 
fiu.  oz.),  put  100  cubic  centimetres  (3.38  flu.  ozs.)  of  a  satu- 
rated solution  of  gypsum  into  a  beaker,  color  the  liquid  with 
some  reddened  litmus  tincture,  and  add  from  a  0.10  cubic 
centimetre  (0.027  flu.  dr.)  graduated  pipette  or  burette,  so 
much  of  the  soap  solution  as  will  cause  the  red  color  again  to 
become  blue.  To  reach  this  point  with  more  accuracy,  there 
is  next  to  the  first  beaker  a  second  beaker,  also  tilled  with 
gypsum  water,  which  by  means  of  litmus  tincture  has  been 
colored  blue.  If  on  the  appearance  of  the  desired  blue  shade 
of  color,  20  cubic  centimetres  (0.676  flu.  oz.)  have  been 
used  of  the  soap  solution,  it  will  have  the  correct  titer; 
but  if  less  have  been  used,  it  must  in  the  same  proportion  be 
diluted  with  so  much  weak  alcohol,  that  20  cubic  centimetres 
(0.676  flu.  oz.)  are  reached.  Supposing  cubic  centi- 
metres (0.422  flu.  oz.)  had  been  required,  then  to  every 
12.5  cubic  centimetres  of  soap  solution  7.5  cubic  centimetres 
(U.248  flu.  oz.)  alcohol  would  be  needed  ;  if  of  the  first  11 
(0.371  flu.  oz.)  was  had,  so  would  need 

12.5  :  1000  =  7.5  :  X  =  600  cubic  centimetres  (20.28  flu. 
ozs.)  alcohol 

5 


66  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

to  be  added,  so  that  1600  cubic  centimetres  (1.689  quarts) 
soap  solution  are  formed,  which  accordingly  is  ready  for  use. 

Since  the  waters  which  are  to  be  tested  as  to  their  degrees 
of  hardness,  almost  without  exception,  contain  larger  or 
smaller  quantities  of  bicarbonate  of  lime,  which  reddens  the 
tincfure  of  litmus,  only  by  boiling  can  the  carbonic  acid  as 
an  insoluble  carbonate  of  lime  separate.  The  waters  must 
be  boiled  about  five  minutes  before  commencing  to  add  the 
soap  solution,  and  then  be  mixed  with  so  much  nitric  acid  that 
the  liquid  obtains  a  light  red  color.  If  a  nitric  acid  of  a 
certain  strength  is  applied — for  instance  of  one-tenth  equiva- 
lent to  the  liter  (1.05  quart)  (54  :  10,000) — then  the  quantity 
of  the  nitric  acid  used  will  also  prove  the  hardness  of  the 
water,  since  1  cubic  centimetre  (0.27  flu.  dr.)  of  such  an  acid 
corresponds  to  about  2  cubic  centimetres  (0.54  flu.  dr.)  of  the 
normal  soap  solution.  If,  therefore,  in  the  testing  of  a  well- 
water  8  cubic  centimetres  (0.270  flu.  oz.)  of  the  latter  acid 
have  been  used,  while,  on  the  other  hand,  for  the  solution  of 
the  carbonate  of  lime  4  cubic  centimetres  (0.135  flu.  oz.)  of 
the  ^'(5  standard  nitric  acid  had  been  applied,  it  follows,  there- 
fore, that  2  cubic  centimetres  (0.54  flu.  dr.)  of  the  soap  solu- 
tion have  to  be  brouo-ht  into  account  for  the  carbonate  and 
nitrate  of  lime,  and  6  cubic  centimetres  (0.203  flu.  oz.),  hence 
6°  for  the  permanent  degree  of  hardness. 

Every  degree  of  hardness  corresponds  to  100.  cubic  centi- 
metres (3.38  flu.  ozs.)  12  milligrammes  (0.18  grains)  gyp- 
sum, or  5  milligrammes  (0.077  grain)  of  pure  lime,  so  that  for 
the  single  degrees  of  hardness  the  following  values  are 
proved,  which  permit  an  approximate  conclusion  as  to  the 
soap  which  is  decomposed  by  the  water. 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  67 


Degree 

In  ICOO  kg.  water. 

101)0  Kg.  01 

Degree 

In  1000  kg.  water. 

lOUK  Kg.  01 

of 

water  decom- 

of 

water  decom- 

hard- 

pose soap 

hard- 

pose soap 

ness. 

with  28  p.c. 

ness. 

with  28  p.c. 

Lime. 

Gypsum. 

water. 

Lime 

water. 

20 

1.01  kg. 
0.96  " 

2.45  kg. 

14.75  kg. 

10 

0.50  kg. 
0.45 

1.23  kg. 

7.31kg. 

19 

2.33  '* 

14.02 

9 

1.10 

6.58  " 

0.91  " 

2.21  " 

13.30  " 

8 

0.40  " 

0.98  " 

5.85 

17 

0.86  " 

2.08  " 

12.57  " 

7 

0  35  " 

0.86  " 

5.12  " 

16 

0.81  " 

1.96  " 

11.85  " 

6 

0.30  " 

0.74 

4.89  " 

15 

0.76 

1.84  " 

11.12  " 

5 

0.25  " 

0.61  " 

3.66  " 

14 

0  71  " 

1.72  " 

10.39  " 

4 

0.20  " 

0.49  " 

2.93  " 

13 

0.66  " 

1.59  " 

9.67  " 

3 

0.15  " 

0.37  " 

2.19  " 

12 

0.61  " 

1.47 

8.94  " 

2 

0.10  " 

0.25  " 

1.46 

11 

0.56  " 

1.35  " 

8.21  " 

1 

0.05  " 

0.12  " 

0.73  " 

But  there  are  some  waters  the  hardness  of  which  ex- 
ceeds 20°,  i.  e.,  such,  as  besides  a  large  amount  of  gypsum 
contain  also  chloride  of  calcium  and  dolomite  salts,  which 
decompose  a  larger  amount  of  soap.  The  purest  waters  are 
rain  and  snow  waters.  River  water  is  generally  sufficiently 
pure  for  making  soap  and  lye.  A  simple  remedy  for  waters 
containing  lime,  is  a  solution  of  silicate  of  soda  of  20°  B.,  5 
per  cent,  of  which  added  to  the  water  will  cause  the  lime  to 
precipitate  and  leave  the  clear  water  sufficiently  pure  for  use. 

Salt. 

Culinary  salt  or  sodium  chloride  playing  an  important 
part  in  the  manipulation  of  soap  it  is  necessary  to  give  some 
of  its  characteristics  and  the  impurities  that  impair  its  use- 
fulness and  cause  a  loss  of  soap. 

Most  of  the  salt  of  commerce  contains  forei2:n  salts  such  as 
chloride  of  magnesium,  sulphate  of  soda,  gypsum,  etc.  These 
impurities  decompose  a  large  proportion  of  soap,  forming 
metallic  and  insoluble  soaps  that  are  either  precipitated  or  if 
held  in  the  soap  impair  its  detersive  qualities  and  injure  its 
appearance.  The  salt  furnished  by  the  evaporation  of  sea 
water  is  so  very  impure  that  it  should  be  entirely  avoided. 
That  from  mineral  springs  is  very  much  better  though  often 
contaminated  with  organic  matter,  while  that  made  from  the 
salt  mines  or  rock  salt  has,  as  a  rule,  the  fewest  impurities, 
although  it  is  never  entirely  pure. 


68  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLfiS. 


In  boiling  soap,  salt  is  so  important  a  material  for  refining 
that  the  soap-maker  should  pay  proper  attention  to  procur- 
ing it  reasonably  pure,  otherwise  he  may  fail  in  obtaining  a 
good  color,  or  he  may  lose  by  the  decomposed  soap  and  alkali 
carried  off  with  the  waste  lye.  Should  he  suspect  that  his 
salt  has  many  impurities  he  can  refine  it  in  the  manner 
indicated  for  hard  water,  viz.,  with  silicate  of  soda.  This 
process  is  quite  simple,  it  being  only  necessary  to  dissolve 
the  salt  in  a  suitable  quantity  of  warm  water  and  to  add  the 
solution  of  silicate  of  soda  in  the  proportion  of  say  5  per 
cent.,  when  after  stirring  for  a  time  and  being  left  to  rest,  it 
will  carry  down  with  the  precipitate  almost  all  of  the  lime 
and  other  salts,  and  the  soap-maker  may  use  the  upper  clear 
portion  with  confidence.*  By  means  of  the  crystal  carbonate 
of  soda  a  solution  of  culinary  salt  can  also  be  somewhat 
purified,  as  the  contaminating  salts  are  thereby  changed  into 
insoluble  carbonates  which  precipitate  and  can  easily  be 
separated. 

Fats  and  Oils. 

Both  fats  and  oils  occur  as  the  constituents  of  animals  as 
well  as  plants;  in  animals  these  substances  are  deposited  in 
particular  tissues  in  larger  quantities,  and  are  found  in  all 
parts  of  plants,  principally  in  the  seeds  and  fruit;  and  are 
characterized  by  their  physical  and  chemical  properties. 
Such  as  are  liquid  at  ordinary  temperatures  are  termed  fat 
oils,  those  that  have  a  soft  consistency  are  called  lard  or 
butter,  while  those  that  have  a  higher  melting  point  and  are 
solid  at  the  normal  temperature,  are  classified  with  tallow  and 
suet.  In  a  pure  state  they  are  generally  colorless  and  but  of 
faint  odor  and  are  of  an  average  specific  gravity  of  0.9. 
They  are  insoluble  in  water  and  but  slightly  soluble  in 
alcohol,  but  freely  in  ether  and  carbon  bisulphide  and  in 
volatile  oils.  Some  fat  oils  absorb  oxygen  and  dry  up  and 
are  called  drying  oils,  others  only  assume  a  rancid  state 
when  exposed  to  the  air. 

When  heated  to  250°  or  300°  C.  (482°  or  572^  F.)  they 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  69 


are  decomposed',  forming  volatile  acids  of  a  disagreeable  and 
irritating  odor.  At  a  still  greater  heat  they  form  a  com- 
bustible gas  which  has  three  times  the  illuminating  power 
of  coal  gas  and  is  very  much  purer. 

The  fatty  bodies  are  of  very  great  importance  in  numerous 
industries,  in  domestic  economy  and  for  lubricating  ma- 
chinery, but  perhaps  their  greatest  and  most  important  use 
is  in  the  fabrication  of  soap  and  candies,  so  indispensable  in 
all  civilized  countries. 

We  have  already  mentioned  that  the  true  properties  and 
constituents  of  oils  and  fats  were  unknown  until  Chevreul, 
Scheele,  and  others  published  the  results  of  their  researches, 
their  nature  and  elementary  composition,  and  gave  a  scientific 
character  to  all  manufactures  into  which  they  entered  and 
particularly  to  the  making  of  soap  and  candles.  These  re- 
searches have  been  fully  confirmed  by  all  later  experiments, 
and  possess  so  much  interest  and  importance  that  we  shall 
endeavor  to  give  this  branch  of  the  subject  thorough  and 
complete  treatment. 

The  fats  and  oils  finding  application  in  the  manufacture 
of  soap  are  either  of  vegetable  or  animal  origin,  and  either 
liquid,  as  linseed  oil,  hemp  oil,  olive  oil,  poppy  oil,  fish  oil, 
etc.,  or  they  are  more  or  less  solid,  as  tallow,  lard,  palm  oil, 
cocoa-nut  oil,  etc.  Under  the  influence  of  alkalies,  and  the 
bases  of  metallic  oxides  generally,  they  are  all  decomposed 
into  various  sebacic  acids  and  glycerine. 

Liquid  fats,  i.  e.  oils,  assume  at  a  low  temperature  a  firm 
consistency  (linseed  oil  only  at  27°  below  0  C,  16.6^  F.), 
while  the  solid  fats,  i.  g.,  tallow,  etc.,  at  an  increased  tem- 
perature become  oily  (some  even  below  100°  C,  212°  F.). 

All  fats  and  fatty  oils  are  according  to  their  chemical 
composition  called  glycerides,  i.  g.,  glycerine  combinations 
in  w4iich  are  comprised  according  to  the  theoretical  view,  of 
3  atoms  of  water  or  3  atoms  of  hydrogen  of  the  glycerine, 
w^hich  is  according  to  the  general  chemical  formula  CgHgOg, 
and  3  atoms  or  equivalents  of  sebacic  acids. 

According  to  the  first  or  older  view  glycerine  is  considered 
=  CgH^O,  -t-  3H0,  and  contains,  according  to  this  view,  a  sub- 
stance, the  so-called  glyceryl-oxide  or  lipyloxide,  =  CgH503, 
which  occurs  in  glycerine  with  3  equivalents  of  water,  but  ap- 


70  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


pears  in  the  fats  combined  with  3  equivalents  of  sebacic  acids. 
In  the  fats  we  find  especially  pal  mitic  acid  of  gl  jceryl-oxide  or 
so-called  palmitin  =0^11503  -f  3(C32H3j03),  furthermore  stearic 
acid  glyceryl-oxide,  so-called  stearine  =  CgHjOg  +  8(035113303), 
and  finally  oleic  aid  of  glyceryl-oxide  or  so-called  oleine  = 
C^H^O,  +  3(C,,H3303). 

According  to  a  more  modern  view,  glycerine  is  con- 
sidered as  a  so-called  triple  acid  alcohol  =  Og^^  |  Og,  in 

which  the  three  separately  written  hydrogen  equivalents 
(H3)  are  represented  in  the  fats  by  3  equivalents  of  the  above- 
mentioned  sebacic  acids.    The  palmitin  of  the  fats  is  accord- 
Pi  ) 

ing  to  this  tripalmitin  =0g  ^TT^  s  [Og*,  the  stearine  is 
tristearine  =  Og  /p"^TT         [  Og ;  the  oleine  is  trioleine  = 

The  pure  fats  of  the  vegetable  as  well  as  of  the  animal 
kingdom,  the  tallows  no  less  than  the  lards  and  oils,  are  not 
combinations  of  merely  one  sebacic  acid  with  the  above  men- 
tioned glyceryl-oxide,  but  contain  altogether  at  least  one 
liquid  fat,  i.  e.,  the  combination  of  one  solid  and  one  liquid 
acid,  with  glycol-oxide.  These  combinations  have  a  con- 
sistency similar  to  the  sebacic  acids  contained  in  them,  but 
are  somewhat  more  fusible.  Many  fats  of  the  most  varied 
origin  differ  in  the  pure  state  only  by  the  relative  quantities 
of  the  same  solid  and  liquid  combinations,  which  they  obtain 
one  from  the  other  ;  for  instance,  olive  oil  and  human  fat ; 
others,  howeverj  contain  the  same  solid  fat  as  these,  but  as 
to  their  combinations  and  their  properties  are  an  essentially 
different  liquid  acid  in  combination  with  the  glyceryl-oxide. 
In  others  again,  for  instance  palm  oil  and  cocoa-nut  oil,  the 
solid  acid  certainly,  and  perhaps  also  the  liquid  acid,  is  a  pecu- 
liar acid.  In  general,  we  have  at  the  ordinary  temperature  the 
firm  combinations  called  stearines,  and  the  liquid  combinations 
called  oleines.  However,  we  mean  by  stearine,  stearic  gly- 
ceryl-oxide, the  combination  of  a  specific  accurately  known 
solid  acid,  which  is  contained  in  many  animal  fats,  especially 
in  that  of  oxen,  sheep,  etc.   By  the  term  oleine  or  elaine,  oleic 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  71 


or  elaic  acid  glyceryl-oxide,  we  mean  the  liquid  combination 
which  occurs  in  a  great  many  animal  fats,  as  well  as  in  many 
vegetable  fats,  and  in  both  the  same  chemical  combination 
exists.  A  number  of  vegetable  oils,  however,  contain  another 
oleic  acid,  which  is  sometimes  called  oleine  acid.  It  possesses 
the  property  of  drying  to  a  tough  solid  body  when  exposed  to 
the  air,  while  common  oleic  acid  only  thickens  to  a  smeary 
fatty  substance.  For  this  reason  the  oils  which  contain  the 
former  are  called  drying  oils,  and  the  others  fat  oils. 

The  second  combination  of  a  solid  sebacic  acid  with 
glyceryl-oxide,  which  is  sometimes  mixed  with  stearine  and 
again  with  oleine,  is  called  palmitin  (margarine),  and  the  acid 
palmitic  acid  (margaric  acid)  is  next  to  the  oleic  acid  the 
most  extensively  distributed  sebasic  acid.  It  is  found  as  a 
solid  ingredient  along  with  stearic  acid  in  ox-tallow,  and  in 
fat  as  well  as  drying  oils,  and  palm  oil.  The  pure  combina- 
tions of  the  above-mentioned  substances  are  odorless ;  but 
the  most  of  the  raw  fats,  those  of  the  vegetable  kingdom  as 
well  as  of  the  animal  kingdom,  possess  a  specific  odor,  by 
which  they  may  be  distinguished  from  one  another.  In 
some,  it  orignates  from  an  admixture  of  volatile  oils,  for 
instance,  in  the  oil  of  mace ;  in  others  from  glyceryl-oxide 
combinations  with  volatile  acids,  for  instance,  lactic  acid, 
valerianic  acid,  capronic  and  hircinic  acids,  as  in  mutton 
tallow;  in  others,  as  in  linseed  oil,  the  odor  depends  upon 
unknown  admixtures. 

To  the  touch  the  fats  are  known  by  their  specific  lubricity, 
in  water  they  are  all  insoluble,  most  of  them  also  in  alcohol, 
excepting  castor  oil.  Heated  alcohol  takes  up  a  goodly 
amount  of  the  fats,  which  after  cooling  ofif  again  almost 
entirely  separate,  but  they  are  freely  soluble  in  ether,  volatile 
oils,  sulphuret  of  carbon,  chloroform,  acetone,  and  pyrolig- 
neous  acid  (wood  spirit).  They  are  rich  in  hydrogen  and 
oxygen,  of  the  latter  they  contain  70  to  80  per  cent,  but  nitro- 
gen (azote)  is  not  contained  therein.  Their  specific  gravity 
is  always  less  than  that  of  water,  and  changes  according  to 
the  kind  of  fat  between  0.910,  and  0.930  at  15°  C.  (59°  F.). 

The  fats  in  fluid  condition  expand  at  every  increase  of  tem- 


72 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


perature  over  1°  C.  (33.8°  F.)  by  ysV^  joVu  of  their  volume, 
so  that  at  120°  C.  (248°  F.)  they  have  j'^  more  volume  than 
at  0°  C.  (32°  F.).  In  the  dark  they  become  phosphorescent, 
by  a  slight  increase  of  temperature ;  the  real  fat  oils  and  fats 
boil  only  at  170  to  250°  C.  (338  to  482°  F.),the  drying  oils, 
however,  beween  100  and  115°  0.  (212  and  239°  F.). 

No  fat  can  be  distilled  without  decomposition ;  while  it 
boils  at  the  high  temperature  of  800°  C.  (572°  F.),  the  escap- 
ing vapors  are  not  those  of  the  undecomposed  oils,  but  those 
of  the  formed  products  of  decomposition,  which,  according 
to  the  applied  temperature,  as  well  as  to  the  amount  or  kind 
of  the  divers  sebacic  acids  contained  therein,  vary  very  much. 
The  glyceryl-oxide  is  first  decomposed,  a  very  volatile  body 
is  formed,  which  is  violently  irritating  to  the  eyes,  at  the 
ordinary  temperature  is  liquid,  soluble  in  water,  and  is  called 
acrolein.  By  this  property,  it  is  easily  ascertained  whether 
a  fat-like  substance  is  really  fat,  a  combination  of  glyceryl- 
oxide,  or  not;  for  the  least  amount  of  glyceryl-oxide  makes 
itself  noticeable  by  the  intensely  sharp  smell  of  acrolein. 
The  oleic  acid,  too,  will  be  in  a  great  measure  decomposed, 
and  but  little  distils  over  unchanged.  From  it  is  formed 
the  so-called  sebacic  acid,  with  a  series  of  substances  such 
as  carburetted  hydrogen  gas,  the  so-called  oil-forming  gas 
(chiefly  illuminating  gas)  and  like  carburetted  substances. 
If  stearic  acid  be  present,  it  separates  in  palmitic  acid  and 
also  in  several  carburetted  substances^  and  even  the  palmitic 
acid  does  not  distil  entirely  over  unmixed,  although  a  large 
pait  thereof  is  found  among  the  products  of  the  distillation. 

If  the  pressed  or  rendered  fats  are  exposed  to  the  air,  they 
absorb  oxygen,  at  first  slowly  but  afterwards  more  rapidly. 
During  the  process  the  so-called  drying  oils  cover  themselves 
with  a  skin,  and  thereby  withstand  the  influence  of  the  air 
much  longer.  The  other  oils  or  fats  become  somewhat  tough 
and  thick,  and  gain  a  disagreeable  odor,  show  an  acid  reaction, 
and  taste  sharp  and  are  gritty.  This  is  especially  the  case 
when  the  oils  have  absorbed  much  albumen  and  similar  matter 
from  the  organs  of  plants  or  animals  from  which  they  have 
been  obtained.    By  the  shaking  up  of  such  oils  in  hot  water 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  73 


and  a  small  quantity  of  hydrate  of  dolomite,  this  condition, 
which  is  called  rancid^  may  he  changed. 

Many  acids  ahsorb  the  glyceryl-oxide  entirely  or  partly 
from  the  sebacic  acids.  If  a  little  hydrate  of  sulphuric  acid 
for  instance  is  carefully  mixed  with  olive  oil,  so  that  no  heat- 
ing ensues,  glj^cerine  will  be  separated,  which  with  the  sul- 
phuric acid  combines  and  forms  a  compound  of  glycerine  and 
sulphuric  acid,  while  the  sebacic  acid  is  free.  But  if  the 
oil  is  carefully  mixed  with  half  its  volume  of  hydrate  of  sul- 
phuric acid,  then  the  sebacic  acids  combine  also  with  the 
sulphuric  acid  and  form  bodies  which  by  the  addition  of 
water  are  decomposed,  transferring  all  the  sulphuric  acid 
thereto,  in  cold  air  gradually,  by  boiling  at  once,  into  several 
other  acids,  among  which,  however,  neither  palmitic  nor  oleic 
acid  is  found. 

Upon  the  influence  of  sulphuric  acid  on  fats,  rests  in  part 
its  application  in  purifying  the  same.  The  oils  obtained  from 
seeds  by  pressure  are  never  free  from  albumen  and  other 
impurities  ;  a  moderate  addition  of  sulphuric  acid  causes 
these  substances  to  coagulate  and  produce  in  water  soluble 
glycerine  sul[»huric  acid.  If,  on  the  other  hand,  too  much 
sulphuric  acid  is  used,  there  will  be  formed  monomargaric, 
hjdromargaritic,  hydromargaric,  monoleic,  and  hydroleic 
acids,  which  are  very  limpid  and  contain  less  carbonic  acid 
than  oleic  and  margaric  acid. 

In  the  melting  of  tallows  and  animal  membranes,  we 
must  be  careful  in  the  application  of  sulphuric  acid.  A 
large  quantity  of  this  acid  makes  the  melting  easier,  but  we 
obtain,  as  experience  teaches,  tallow  which  is  very  fusible, 
which  for  the  manufacture  of  candles  is  not  desirable,  and 
obviously  originates  from  the  formation  of  hydromargaric 
acid,  etc. 

In  order  to  obtain  the  hardest  possible  tallow  for  chandlers, 
such  as  even  in  warm  weather  may  be  moulded  and  may  be 
easily  taken  from  the  moulds,  the  melted  tallow  should  be 
permitted  to  cool  off  very  slowly.  Stearine  and  palmitin 
will  then  separate  in  noticeable  crystals,  and  in  a  tempera- 
ture of  20°  to  25°  C.  (68^  to  77^  F.),  a  large  part  of  the  olein 


74 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


can  be  removed  by  pressing.  Thus  a  tallow  is  obtained 
which  at  all  seasons  of  the  year  may  be  manufactured  into 
candles.  These  are  harder,  less  fusible,  and  whiter,  since  the 
olein  is  generally  of  a  yellowish  hue.  Such  candles  are  in 
the  market  under  the  name  of  stearine  candles,  which  must 
not  be  confounded  with  stearic  acid  candles,  which  are  some- 
times also  called  stearine  candles.  This  will  be  more  fully 
explained  in  the  section  on  candles. 

Diluted  nitric  acid  at  first  acts  on  the  oils  similarly  to  sul- 
phuric acid.  It  sets  one  part  of  the  glycerine  free.  Con- 
centrated acid,  however,  reacts  very  strongly  with  it ;  they 
froth  violently,  and  at  times  even  ignition  ensues.  A  great 
number  of  products  of  oxidation  are  thus  formed — volatile 
and  less  volatile  acids. 

Nitric  acid  causes  a  very  singular  change  in  the  olein,  the 
sebacic  acid,  and  the  fats.  The  olein  of  the  drying  oils  does 
not  undergo  this  change.  Without  withdrawing  from  the 
olein  its  glyceryl  oxide,  the  nitric  acid  will  change  it  at  the 
ordinary  temperature  into  a  white  body,  called  elaidin,  and 
the  acid  produced  therefrom,  the  elaiodic  acid,  is  not  liquid 
like  the  oleic  acid,  but  solid.  Both  these  acids  have  the  same 
chemical  composition. 

The  salifiable  bases  decompose,  as  has  already  been  ob- 
served, the  combination  of  the  sebacic  acid  with  the  glj^ceryl 
oxide,  and  unite  with  the  stearic,  palmitic,  and  oleic  acids, 
and  all  other  sebacic  acids,  into  salts,  which  are  called  soaps 
when  the  base  is  an  alkali,  and  plasters  when  the  base  is 
protoxide  of  lead  (litharge).  The  glyceryl  oxide  separates,  by 
the  combining  of  1  eq.  of  the  same  with  3  eq.  of  water,  into 
glycerine.  Caustic  ammonia  produces  the  same  decomposi- 
tion, but  only  after  a  very  long  time ;  or  it  unites  with  the 
oils  into  a  thick  and  milky  fluid,  which  is  known  under  the 
name  of  volatile  liniment.  Carbonated  fixed  alkalies  form 
also  creamy  liquids,  from  w^hich,  however,  diluted  acids  sepa- 
rate the  fat  unchanged.  Culinary  salt  and  sulphate  of  copper 
are  dissolved  by  the  fats  without  changing  them. 

The  number  of  the  various  fats  found  in  the  animal  and 
vegetable  kingdoms  is  infinitely  large;  almost  every  kind 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  75 


possesses  a  fat  or  oil  which,  either  on  account  of  its  smell, 
color,  etc.,  differs  from  the  other.  In  a  great  part  these  dif- 
ferences exist  only  in  the  various  quantitative  mixtures  of 
the  liquid  and  solid  parts,  and  are  caused  by  small,  unessen- 
tial admixtures,  a  small  amount  of  volatile  substances  which 
are  to  be  considered  as  unessential  to  the  fat.  There  have 
been  very  many  different  kinds  of  solid  and  liquid  fats  found 
which  have  not  yet  been  thoroughly  examined. 

Fats  of  Animal  Origin. 

Tallows  are  those  fats  or  greases  obtained  from  the  ox,  the 
sheep,  the  goat,  and  the  deer,  and  are  the  hardest,  having 
the  highest  melting  point.  The  first  two  named  find  the 
most  prominent  application  in  the  manufacture  of  soaps,  and 
are  mixtures  of  oleine,  margarine,  and  stearine,  in  varying 
proportions,  according  to  the  age,  the  season,  and  the  nature 
of  the  food.  Animals  fed  upon  dry  food  furnish  the  most 
solid  tallow^,  that  of  those  that  are  pastured  is  less  so,  while 
those  fed  upon  swiil  furnish  a  very  soft  grade.  It  is  also 
noticed  that  fat  produced  in  summer  is  softer  than  winter 
fat.  The  fat  occurs  enveloped  in  very  thin  cellular  tissues 
which  are  moist  in  fresh  tallow  and  are  easily  decomposed  and 
soon  undergo  a  change  in  the  air.  It  is  necessary  therefore, 
especially  in  summer,  to  keep  it  in  a  cool  place  or  at  once  to 
separate  it  from  the  membranes  by  rendering.  Besides  the 
three  constituents  above  mentioned,  tallow  contains  the 
glycerides  of  some  volatile  sebacic  acids,  as  lactic,  capric, 
capronic,  and  valerianic  acids,  besides  some  peculiar  matters 
not  yet  fully  tested  and  explained. 

To  obtain  the  tallow  from  the  membranes  which  surround 
it,  the  fatty  tissues  are  cut  into  small  cubes,  placed  in  a 
suitable  vessel  and  exposed  to  a  heat  which  exceeds  that  of 
boiling  water.  In  the  beat  the  membranes  are  destroyed,  the 
melted  tallow  runs  out  and  can  be  separated  from  the  mem- 
brane by  straining.  This  process  has  been  in  practice  a  long 
time  and  is  so  still.  Sometimes  a  still  higher  temperature 
is  applied  in  order  to  cause  the  residium  to  undergo  a 


76 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


roasting,  thereby  trying  to  obtain  a  greater  yield  of  pure 
tallow.  In  general  though,  this  method  remains  imperfect 
and  a  larger  or  smaller  loss  of  tallow  is  sustained,  much 
remaining  in  the  tissues,  which  are  but  imperfectly  opened  by 
this  operation  and  become  so  hard  that  they  yield  the  tallow 
under  the  press  with  difficulty.  Furthermore  it  is  an  impos- 
sibility to  obtain  an  even  temperature  with  which  to  operate 
through  the  entire  melting  process.  On  the  bottom  it  be- 
comes too  high,  to  the  detriment  of  the  color  and  quality  of 
the  tallow.  Finally  during  the  melting  process  are  devel- 
oped from  the  animal  substances  gaseous  and  other  vapors  of 
a  disgusting  odor. 

The  application  of  steam  in  lieu  of  a  free  fire  is  but  a 
slight  improvement,  because  the  temperature  remains  too 
low  and  besides  by  the  immediate  contact  of  steam  with  the 
fat,  the  substance  of  the  membrane  is  changed  into  glue, 
which  can  be  separated  from  the  tallow  only  with  great  diffi- 
culty. In  hermetically  sealed  vessels  by  an  increased  pressure 
and  a  direct  stream  of  steam  the  raw  tallow  may  be  melted, 
the  fat  finally  separating  from  the  glue  solution  which  settles 
on  the  bottom. 

That  in  the  process  of  mere  melting  the  membrane  yields  the 
fat  with  so  much  difficulty,  is  demonstrated  especially  in  the 
fact  that  the  tissues  are  not  completely  destroyed  and  opened. 
To  manipulate  to  a  more  complete  opening,  various  means 
have  been  proposed  and  applied,  which  answer  the  purpose 
equally  well  so  that  one  or  the  other  is  brought  into  use. 
Most  convenient  is  the  method  of  allowing  the  lumps  of  fat, 
instead  of  cutting  them  into  small  pieces,  to  pass  through 
narrow  rollers  whereby  all  tissues  are  opened,  and  after  this 
the  tallow  may  be  rendered  in  the  heat.  Another  process 
(by  Evrard)  consists  in  the  mixing  and  warming  of  300  parts 
of  cut  tallow  with  caustic  natron  lye  (made  of  1  part  calcined 
soda  dissolved  in  200  }.>arts  water).  The  odorous  substances, 
partly  volatile  acids,  combine  with  the  natron  and  remain  in 
the  lye  dissolved,  while  the  pure  fat  is  separated.  By  this 
mode  Faiszt  obtained  from  100  parts  of  raw,  88  parts  of  pure 
tallow,  and  from  the  lye  by  the  addition  of  acid  8  parts  more, 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  77 


hence  together  96  parts.  In  this  manner  all  the  fat  may  be 
obtained,  and  yet  no  special  advantage  is  found  in  this  pro- 
cess, especially  if  we  consider  the  labor,  and  also  the  circum- 
stance that  in  this  case  no  greaves  or  cracklings  are  yielded 
which  find  a  good  and  profitable  use  in  feeding  swine  and  dogs. 

In  the  same  manner  D'Arcet,  according  to  his  acknowl- 
edged excellent  method,  brings  diluted  sulphuric  acid  to 
operate  on  the  raw  tallow  whereby  the  important  advantage 
is  had,  that,  by  the  cbemical  destruction  and  opening  of  the 
tissues,  the  development  of  the  fetid  vapors  is  lessened  and 
they  become  more  bearable.  According  to  D'Arcet  the  raw 
tallow  is  melted  with  half  its  volume  of  water,  to  which 
has  previously  been  added  3.3  per  cent,  of  sulphuric  acid, 
keeping  the  entire  mass  boiling  until  the  separation  of  fat 
and  tissues  is  finished.  Although  this  operation  was  origi- 
nally calculated  for  an  open  fire,  it  may  nevertheless  be  per- 
formed over  steam,  since  by  the  acid  the  separation  of  fat  is 
furthered  in  a  high  degree.  In  the  apparatus  of  Taulet  the 
heating  of  steam  is  performed  from  the  outside,  in  that  of 
Chamby  by  a  direct  introduction  of  steam,  whereby  the 
greaves  or  cracklings  are  so  loosened  that  they  are  pressed 
out  with  ease,  or  by  mere  reboiling  render  the  tallow  com- 
pletely. Experiments  with  the  first  apparatus  yielded  2  to  4 
per  cent,  more  than  the  operation  over  an  open  fire.  With 
regard  to  the  direct  introduction  of  steam,  experience  has 
taught  to  apply  less  water  by  an  increase  of  acid,  i.  6.,  to 
apply  about  one-fifth  water  with  6  per  cent,  acid,  since  by 
means  of  the  condensed  water  the  proper  proportion  is  estab- 
lished. 

On  the  same  principle  as  that  of  D'Arcet,  the  method  of 
Lefevere  is  founded.  He  prescribes  the  maceration  of  the  cut- 
up  tallow  for  three  or  four  days  in  the  diluted  acid,  and  then 
the  remelting  of  it  in  fresh  water.  As  long  as  fresh  tallow, 
or  at  least  some  which  is  not  too  old,  is  worked,  the  methods 
before  mentioned  are  ample,  even  the  simple  rendering,  espe- 
cially if  the  raw  tallow  has  been  pressed  through  rollers.  It 
matters  not  whether  by  the  one  or  the  other  method  a  few  per 
cent,  of  fat  more  or  less  are  gained,  if  the  remaining  greaves 


78 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


can  be  used  for  feeding  cattle  and  swine.  Experiments 
of  comparison  whether  the  yield  by  the  one  or  the  other 
method  of  melting  tallow  is  more  profitable  are  still  wanting. 
The  statement  that  so  much  pure  tallow  was  obtained  from 
50  kilogrammes  means  nothing,  since  the  raw  tallow  is  un- 
equal in  fat,  and  yields  at  one  time  more,  at  others  less,  so 
that  a  superabundance  of  membranes  is  on  hand.  The  real 
drawback  that  presents  itself  in  the  rendering  out  by  melt- 
ing is  the  unbearable  smell,  which  becomes,  not  only  for  the 
immediate  neighborhood  but  for  a  wide  circle,  a  source  of 
the  greatest  nuisance,  so  that  especially  in  larger  cities  fre- 
quent complaints  are  entered  against  this  evil.  Many  pro- 
positions have  therefore  been  made,  to  have  the  rendering  of 
tallow  performed  in  such  a  manner  that  the  bad  smell  may  not 
appear.  The  most  thorough  investigations  have  been  made 
by  Stein,  and  later  by  Grodhaus  and  Fink,  in  Darmstadt. 
It  is  known  that  the  smell  of  the  bad  tallow  is  caused  by 
the  decaying  of  the  membranous  parts,  which  thereby  taint 
the  fat  which  in  a  pure  state  is  less  changeable.  The  chemi- 
cal change  must  have  great  similarity  with  that  which  en- 
sues in  the  formation  of  cheese,  wherein  fat  and  azotic 
substances  by  mutual  contact  succumb  to  corruption.  In 
this  case  at  least  so  much  is  known — that  the  smell  emanates 
chiefly  from  acids  which  develop  their  smell  not  only  while 
free  but  even  while  latent  in  bases.  Resting  on  this,  Stein 
deemed  it  possible  to  remove  the  fetid  smell  of  the  tallows 
melting  by  a  double  principle,  by  either  suppressing  the 
corruption  or  by  making  their  bad  smelling  product  odorless. 
The  experiments  which  Stein  made  in- the  lirst  direction  were 
whereby  he  applied  either  antiseptics, as  for  instance  sulphuric 
acid  or  tannin,  or  such  substances  as  destroy  putrids,  as  neutral 
chromate  of  potassa,  hypermanganesic  aeid  with  sulphuric 
acid  and  also  nitric  acid ;  all  these  however  have  not  had 
a  satisfactory  result,  and  the  required  operations  were  more- 
over too  complicated. 

Stein  therefore  searched  for  the  other  principle  by  disin- 
fecting the  odorous  products  and  thus  removing  the  trouble 
caused  in  rendering  tallow.   He  then  started  with  the  belief 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  79 


that  they  are  predominant  volatile  oils,  so  that  it  was  neces- 
sary to  change  them  into  salts,  which  on  their  part  would 
be  without  smell  or  of  a  lesser  odor.  In  this  case  too  the 
purpose  could  obviously  be  reached  in  a  dual  manner.  The 
salts  mentioned  could  be  formed  in  the  liquid  itself,  or,  since 
the  odoriferous  acids  must  needs  be  volatile,  could  be  formed 
outside.  For  the  first  case  lime-water  was  tried,  which  mani- 
festly must  needs  work  similarly  to  Evrard's  method  (lye  of 
soda),  but  in  preference  to  this  possessed  the  undeniable 
advantage  of  an  always  even  and  very  great  degree  of 
dilution,  so  that  the  free  acids  in  all  probability  became 
neutralized,  but  no  fat  was  saponified,  and  possibly  the  lime 
combinations  of  the  acid  were  of  a  less  fetid  smell  than 
the  natron  combinations.  In  fact  the  smell  decreased  in  a 
noticeable  manner  when  it  was  placed  in  lime-water;  but 
when  it  was  melted  therewith,  the  smell  increased,  so  that 
the  application  of  lime-water  must  be  avoided.  In  a  very 
ingenious  manner  Stein  now  tried  the  conversion  of  the  bad 
smelling  acids  into  ethyl-oxide  salts,  which  have  even  an 
agreeable  smell.  Although  a  very  successful  result  was 
hereby  reached  because  the  smell  vanished  and  did  not  re- 
appear even  in  the  process  of  melting,  however  another 
circumstance  happened  which  retarded  the  process.  The 
sulphuric  acid  which  separates  from  the  sulphuric  ether 
acid  (necessary  in  the  forming  of  the  ethyl-oxide)  furthers 
the  solution  of  the  glue  producing  formation,  in  consequence 
whereof  the  formation  of  an  emulsion  ensues  from  which  the 
fat  can  be  separated  only  with  difficulty.  Hence  this  pro- 
cess of  melting  had  also  to  be  abandoned. 

It  now  only  remained  to  cause  the  escaping  odors,  after 
coming  forth,  to  be  made  harmless.  This  process  too  is  based 
on  the  idea  that  these  substances  are  acids,  which  might  be 
bound  by  an  acidifiable  base,  and  for  such  Stein  applied  hy- 
drate of  lime  in  combination  with  coarse-grained  charcoal— 
the  lime  to  retain  the  bad  smelling  acids,  the  coal  the  other 
bad  smelling  combinations.  For  this  purpose  a  5  to  7 J  centi- 
metre (1.96  to  2.94  inch)  wide  sieve-crown,  which  could  be 
placed  steam-tight  upon  the  steamboiler,  which  in  place  of 


80  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


the  sieve  bottom  was  covered  with  canvas,  filled  with  slack- 
ened lime  and  fresh-burned  charcoal  of  hazelnut  size,  and 
thus  placed  upon  the  melting  vessel.  All  vapors  which 
escaped  from  the  latter  had  to  pass  through  the  lime-coal 
mixture,  and  proved  on  their  exit  perfectly  odorless. 

Although  the  melting  of  tallow  under  application  of  the 
described  apparatus,  which  Stein  calls  the  "  charcoal  cover," 
is  sufficient  for  the  strictest  requirements  in  regard  to  the 
objectionable  smell,  this  process  will  not  meet  with  general 
use,  since  it  requires  a  steam-tight  sealing  of  the  charcoal 
cover  upon  the  melting  vessel,  which  in  operations  in  larger 
quantities  is  only  fulHlled  with  difficulty.  To  this  must  be 
added,  that  for  every  renewed  melting  a  new  filling  of  the 
cover  with  lime  and  charcoal  will  be  necessary.  This  pro- 
cess can  only  be  called  practical  if  applied  in  the  melting  by 
steam;  but  if — as  is  still  the  practice  inmost  soap-boiling 
establishments — the  melting  is  performed  over  an  open  fire, 
where  in  the  cover  a  paddle  has  to  be  applied,  in  order  to 
stir  the  tallow,  then  the  products  escape  through  the  opening 
for  the  paddle  and  enter  the  work-room.  To  avoid  this,  the 
cover  and  paddle  ought  to  be  connected  air-tight  by  means 
of  an  India-rubber  hose. 

There  is  therefore  no  doubt,  after  the  above  stated  ex- 
periments of  Stein,  that  the  smell,  which  is  caused  by  the 
melting  of  old  tallow,  may  be  removed  by  chemicals,  in  one 
way  or  another;  the  carrying  out  on  a  larger  scale,  how- 
ever, is  obstructed  by  so  many  difficulties,  that  it  appears 
quite  justifiable  to  reach  the  purpose  by  a  more  simple  and 
secure  remedy.  In  fact  Grodhaus  and  Fink,  of  Darmstadt, 
have  abstained  from  applying  any  chemical  preparation,  and 
endeavored  to  remove  the  evil  in  a  philosophical  way.  Their 
experiments,  which  have  resulted  satisfactorily,  are  in  their 
totalit}^  so  instructive,  that  ^ve  deem  it  entirely  justifiable  to 
report  them  here  in  full. 

The  melting  of  the  tallow  is  performed  either  in  the  boiler 
over  an  open  fire,  or  by  meams  of  steam  melting  in  large  re- 
servoirs made  of  sandstone  or  in  wooden  vats.  It  has  already 
been  mentioned,  that  the  rendering  over  an  open  fire  gives 


MATERIALS  USED  TN  THE  MANUFACTURE  OF  SOAPS.  81 


particular  cause  for  developing  the  bad  smell,  because,  near 
the  end  of  the  melting  process,  the  fleshy  and  sinewy  parts 
in  the  fat,  the  greaves,  are  constantly  burnt,  which  must  be 
avoided  by  constant  stirring.  By  this  stirring  which  can- 
not be  dispensed  with,  the  tallow  upon  the  higher  sides  of 
the  boiler  decomposes,  and  the  products  which  originate 
thereby  are  volatilized. 

For  these  reasons  Grodhaus  and  Fink  believed  that  their 
experiments  should  be  extended  as  w^ell  to  the  dry  melting 
of  tallow  as  to  the  wet  process.  The  wet  method  of  melt- 
ing over  an  open  fire  could  be  employed,  since  by  it  the 
same  process  for  diverting  the  smell  may  be  followed  as  by 
tbe  method  of  dry  melting.  Since  the  endeavors  of  Professor 
Stein  to  avoid  the  formation  of  odors  had  from  the  beo-innino; 
no  favorable  result,  and  the  method  proposed  by  him  to  disin- 
fect the  odoriferous  gases  by  meansof  the  "  coal  cover"  requires 
much  attention  and  expenditure  of  time,  and  for  technical  as 
well  as  economical  reasons  will  hardly  ever  find  application, 
Grodhaus  and  Fink,  therefore,  limited  their  experiments  to 
the  search  for  easier  means  of  destroying  the  developing  fetid 
vapors.  For  these  experiments  two  melting  vats  were  |»laced 
in  juxtaposition,  and  in  them  the  raw  tallow  was  melted  with 
diluted  sulphuric  acid  and  by  means  of  steam  ;  furthermore, 
two  boilers  were  placed  contiguous  to  each  other  over  an  open 
fire  with  their  joints — a  so-called  Russian  chimney,  which 
reached  about  90  centimetres  (35  inches)  above  the  roof  of  the 
one-story  melting  house.  In  the  following  experiments, which 
were  made  for  the  purpose  of  carrying  the  vapors  through  the 
chimney,  through  one  of  the  already  mentioned  boiler-fires,  a 
warmed  chimney  was  used,  because,  if  the  experiments  with 
such  a  low  chimney  would  furnish  favorable  results,  a  higher 
chimney  would  undoubtedly,  wherever  it  existed,  promise 
still  greater  success. 

The  first  experiment  was  to  decide  whether  the  developed 
vapors  by  a  steam  melting  process  could  be  burned  by  means 
of  a  common  boiler  fire.  Hence  one  of  the  above-mentioned 
melting  coops  was  provided  with  a  well  fitting  cover.  In 
this  cover  was  a  hole  7J  centimetres  (2.92  inches)  wide,  over 
6 


82 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


which  a  tin  pipe  was  fixed  and  carried  under  the  grate  of 
one  of  the  boilers  over  an  open  fire.  The  contents  of  one 
of  the  melting  coops  consisted  of  raw  tallow,  of  first  and 
second  qualities,  mixed  Avith  the  required  amount  of  diluted 
sulphuric  acid.  The  fire  under  the  boiler  close  by  burnt  briskly 
when  the  steam  was  admitted  into  the  melting  vat.  As  the 
vapors  developed  therein,  it  was  found  that  they  were  drawn 
off  completely  through  the  tin  pipe  which  had  been  placed 
upon  the  cover,  and  streamed  towards  the  fire ;  they  passed 
freely  through  the  grate,  the  fireplace,  and  the  chimney. 
But  it  very  soon  became  manifest  that  they  extinguished 
the  fire,  which  before  the  commencement  of  the  steam  de- 
velopment burned  very  brightly.  The  admission  of  steam 
into  the  melting  vat  was  now  interrupted,  the  fire  was  again 
started  afresh  and  the  steam  readmitted,  and  the  same  obser-  • 
vation  made  for  a  second  and  a  third  time,  viz.,  that  the  fire 
was  extinguished.  The  experiment  of  drawing  the  vapors 
under  the  grate  of  a  fireplace,  and  there  to  burn  them,  gave 
according  to  this  trial  no  favorable  result. 

A  second  experiment  was  made  in  this  manner:  the  tin  pipe 
which  was  intended  to  carry  the  vapors  from  the  melting  vat 
was  made  to  discharge  itself  into  the  fireplace.  The  vapors 
were  easily  drawn  from  the  melting  vat  into  the  flames,  did 
not  extinguish  the  fire,  and  did  not  have  the  least  smell  at 
the  opening  of  the  chimne^^  and  thus  the  fetid  smelling  pro- 
ducts had  been  destroyed.  This  mode  of  wet  melting,  where 
the  melting  vessel  can  be  supplied  with  a  well  fitting  cover 
and  the  stirring  of  the  contents  does  not  become  necessary, 
can  be  highly  recommended.  For  a  permanent  apparatus  of 
this  kind  a  cast-iron  inlet  pipe  would  answer  the  purpose 
best,  and  should  be  immured  in  the  side  wall  of  the  fireplace 
about  6  centimetres  (2.36  inches)  above  the  grate,  right  into 
the  flame  where  this  iron  pipe  might  be  placed,  while  out- 
side the  wall  a  tin  pipe  might  serve. 

By  a  third  experiment  the  tin  pipe  for  carrying  off  the 
Tapors  was  brought  into  immediate  connection  with  the 
chimney  of  the  boiler  fire.  Here  too  the  success  was  com- 
plete; the  vapors  passed  off  entirely,  and  no  particular  smell 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  83 


could  be  noticed  from  the  chimney  opening.  That  this 
manner  of  carryinjo;  off  the  vapors  operates  in  a  high  chimney 
better  than  in  a  low  chimney  is  self-evident.  Even  if  it 
should  happen  that  in  foul  weather  the  smoke  of  the  chimney 
with  tlie  impregnated  vapors  should  be  pressed  down  into 
the  streets,  the  spreading  of  a  bad  smell  would  not  be  so 
great  as  if  the  vapors  were  dispersed  from  the  melting-room. 

A  further  experiment  was  made  by  which  tallow  was  melted 
over  an  open  fire,  and  where  otherwise  the  well  fitting  wooden 
cover  of  the  melting  kettle  was  supplied  with  an  opening  for 
the  stirring  paddle  ;  in  order  immediately  to  draw  the  vapors 
off  and  admit  them  into  the  fireplace  and  there  to  burn  them 
up,  but  this  operation  led  to  no  practical  result.  The  vapors 
drew  ofi:*  but  slowly  into  the  fire,  and  escaped  when  the  open- 
ing for  stirring  was  not  closed,  or  rather  through  it  and  the 
cracks  between  the  rim  of  the  cover  and  the  kettle,  instead 
of  making  their  escape  through  the  pipe.  This  arrangement 
would  only  be  applicable  when  the  cover  closes  perfectly  and 
an  opetiing  for  the  paddle  either  could  be  entirely  dispensed 
with,  or  a  steam-tight  paddle  could  be  used.  This  experiment, 
changed  in  such  a  manner  that  the  vapors  which  develop 
during  the  melting  over  an  open  fire  were  carried  ofi*  by 
means  of  a  pipe  through  the  chimney,  furnished  a  satisfac- 
tory result.  The  vapors  vanished  so  readily  that  the  opening 
for  the  paddle  might  be  left  open  during  the  entire  period 
of  melting  without  the  least  escape  of  vapors  or  fetid  gases. 

According  to  the  above-described  experiments  we  would 
recommend,  as  the  most  suitable  and  convenient  of  all  the 
means  thus  far  known,  the  carrying  off  of  the  vapors  and 
odoriferous  matters  which  form  and  develop  in  the  operation 
of  either  wet  or  dry  melting,  by  steam  or  over  an  open  fire, 
by  the  application  of  a  pipe  to  the  chimney  of  a  fire  after  it 
18  started.  Where  the  dry  melting  is  preferred,  the  cover 
must  be  made  of  strong  plate-iron  and  be  provided  with  a 
slit  for  the  paddle.  For  the  purpose  of  scooping  out  the 
melted  tallow,  the  cover  must  furthermore  consist  of  two 
parts  which  are  joined  by  hinges.  Only  in  rare  cases,  by 
reason  of  inclement  weather,  may  it  happen  that  the  vapors 


81 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


■which  thus  stream  tlirough  the  chimney  opening  descend 
into  the  street  and  become  noticeable. 

The  facts  re[K)rted  by  Grodhaus  and  Fink  we  can  confirm 
by  our  own  experience;  we  will  not  fail,  liowever,  to  draw 
attention  to  the  fact,  that  the  chimney  used  for  the  carrying 
off  of  vapors  must  be  built  of  well  burned  bricks,  otherwise 
in  its  higher  parts  where  a  condensation  of  water  takes  place 
it  will  gradually  become  soft  and  be  destroyed. 

According  to  tiie  same  method  and  based  on  the  same 
principle  the  melting  of  tallow  is  performed  in  England,  with 
this  exception,  that  the  vapors  are  not,  as  in  the  process  of 
Grodhaus  and  Fink,  carried  immediately  into  the  cliimney, 
but  are  admitted  into  a  wide  pipe  which  is  carried  into 
the  fire.  The  absorption  here  is  so  strong  that  not  only  all 
vapors  out  of  the  melting  kettle,  but  also  a  certain  quantity  of 
air  is  drawn  in  with  it,  and  the  admission  of  the  vapors  will 
be  noticed  at  the  opening  of  every  developing  pipe.  The  com- 
bustion occurs  in  the  mouth  of  the  pipe,  and  the  gases  reach  the 
chimney  almost  entirely  disinfected.  In  other  establishments 
at  Manchester,  the  vapors  are  led  through  a  coke  oven.  In 
the  large  soap  manufactories  of  Cowan  &  Son,  twenty  square 
kettles  for  the  preparation  of  the  fat  are  placed  along  the 
wall;  every  kettle  has  two  openings,  of  which  one  opens 
outside  and  admits  air,  while  the  other  is  in  connection  wuth 
the  ash-pit  in  which  the  draught  may  be  regulated  accord- 
ing to  desire.  All  kettles  communicate  with  a  horizontal 
pipe  which  carries  the  vapors  under  a  particular  fireplace. 

Among  the  many  new  inventions  for  rendering  tallow,  etc., 
in  a  manner  to  avoid  the  offensive  odors  arising  from  the 
operation,  that  invented  by  Yohl  is  perhaps  the  most  success- 
ful. The  kettles  are  provided  with  covers  through  which 
the  gases  are  conducted  and  consumed. 

Figure  1  represents  this  apparatus. 

A  is  the  cast-iron  cauldron,  lined  with  sheet  lead,  and  has 
a  riddled  bottom  dd;  a  is  sl  tap  to  draw  off  the  waste  water; 
b  is  the  tap  through  which  the  fat  is  drawn  ;  p  is  the  fire-grate ; 
B  is  the  door  for  filling ;  c  the  cover,  with  a  mica  plate  S  S ; 
in  the  door  is  also  a  mica  plate  T  for  viewing  the  interior. 


MATERIALS  USED  IN  THE  MANUFACTURE  OP  SOAPS.  85 


D  is  the  vessel  into  which  the  gases  pass  by  the  tube  lo  ;  y  is 
a  cover  with  sand  joints  r  r ;  powdered  lime  is  placed  in  D 
on  oblique  shutes  to  absorb  the  offensive  gases.  Any  liquids 
condensed  flow  off  through  the  pipe  A,  and  the  gases  and 


Fig.  1. 


steam  pass  into  the  condenser  E,  which  contains  coke  moist- 
ened with  sulphuric  acid.  The  liquids  pass  through  the  pipe 
K,  while  the  gases  pass  through  the  tube  F  into  the  ash-pit 
G  under  the  furnace.  G  has  a  door  through  which  a  power- 
ful draft  can  be  sent,  carrying  all  the  gases  into  the  tire  to  be 
there  consumed. 

In  the  rooms  in  which  the  raw  materials  are  stored,  there 
generally  prevails  such  an  unbearable  smell,  which  the  de- 
composing and  putrefying  substances  diffuse,  that  it  has  been 
suggested  to  preserve  the  raw  material  in  closed  spaces, 
these  to  be  connected  by  means  of  a  pipe  with  a  fireplace  or 
with  a  high  chimney  into  which  all  exhalations  and  the  air 
that  enters  from  the  outside  through  the  door  cracks  may 
be  carried.  But  this  evil  might  be  met  in  a  more  efiicacious 
way  ;  for  instance,  by  working  up  the  hides  and  bones,  and 
treating  them  with  phenyl  acid,  which  is  furnished  to  the 
industries  by  Dr.  Calvert.    These  hides  come  from  South 


86 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


America  and  Australia.  Before  they  are  shipped  they  are 
placed  in  water  which  contains  2  to  3  per  cent,  of  phenyl 
(carbolic)  acid.  Hides  treated  in  this  manner  showed  not  a 
trace  of  bad  smell. 

A  similar  contrivance,  especially  for  the  melting  of  tallow 
for  candles  and  soap  manufactories,  is  used  in  the  estab- 
lishment of  Price  of  Battersea,  England.  The  raw  fats  are 
melted  in  large  vessels  which  are  covered  with  flat  hermeti- 
cally fitting  covers  of  lead  and  riveted  to  the  wall.  In  the 
centre  of  the  cover  is  a  square  opening  of  80  centimetres' 
(81  inches)  width,  which  is  supplied  with  a  water  trap,  and 
makes  the  attention  to  the  vessel  convenient.  Upon  the 
cover  is  placed  the  short  end  of  an  inverted  [\_  forming  pipe 
of  15  centimetres'  (5.89  inches)  diameter,  the  other  end  of 
which  being  4J  metres  (14.76  feet)  long  runs  under  the  floor- 
ing of  the  work-room  and  opens  into  a  canjil.  In  the  lower 
part  of  the  pipe  enters  another  pipe  which  is  in  connection 
with  a  force-pump  which  squirts  water  through  a  ro.se  from 
above.  The  vapors  in  the  vessel  condense  as  soon  as  they 
come  in  contact  with  that  stream  of  water,  and  the  descend- 
ing liquid  matter  impregnated  with  all  the  miasms  flows  into 
the  Thames. 

There  are  yet  a  number  of  other  ways  for  rendering  tallow, 
which,  however,  are  mostly  but  modifications  of  the  one  or 
the  other  of  the  above-stated  methods.  Thus,  the  tallow  in 
many  establishments  is  rendered  over  an  open  fire  or  by 
steam,  pressing  the  greaves  and  treating  them  again  sepa- 
rately with  diluted  sulphuric  acid  and  heat.  By  this  means 
the  cellular  tissues  are  destroyed,  the  tallow  flows  out  com- 
pletely, and  is  washed  out  at  first  with  a  sub-lye  and  lastly 
with  water.  In  more  modern  times  in  many  of  the  larger 
soap  manufactories,  rendering  modes  have  been  introduced 
which  are  described  in  our  article  on  lard. 

Lard. 

In  the  United  States  hog's  lard  has  numerous  applications 
in  the  arts,  and  occupies  an  important  place  in  commerce  on 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  87 

account  of  the  large  quantities  produced  and  the  many  useful 
purposes  for  which  it  is  used.    Not  the  least  important  are 

Fig.  2. 


88 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


those  of  soap  and  candles.  Lard  consists  of  about  63  parts  of 
oleine  with  37  parts  of  stearine,  the  oleine  or  oil  having  many 
uses  while  the  stearine  is  used  in  the  fabrication  of  soap  and 
candles.  In  making  candles  it  is  treated  chemically,  produc- 
ing stearic  acid  and  glycerine,  being  rich  in  this  latter  useful 
article;  while  the  oleine  or  red  oil  is  made  into  soap.  This 
process  will  be  detailed  in  our  section  on  candles. 

Lard  is  much  used  in  cooking  and  is  generally  pure,  yet  it 
is  sometimes  sophisticated  with  the  stearine  from  cotton- 
seed oil.  It  is  rendered  or  melted  in  several  ways,  chiefly 
by  the  open  fire,  for  it  is  made  in  nearly  every  farm-house. 
In  cities  and  in  large  operations  steam  is  found  to  i)resent 
the  most  economical  mode.  Many  inventions  are  in  use  for 
rendering  lard,  and  among  them  few  are  more  appropriate 
than  the  one  here  illustrated  for  rendering  tallow  and  lard 
by  steam  and  pressure,  Fig.  2. 

Bendering  by  Steam.  Wilson^s  Process.  The  apparatus 
consists  of  a  series  of  steam-tight  digesters,  each  of  1200  to 
1500  gallons  capacity.  These  digesters  are  composed  of 
boiler-iron  plates  tightly  riveted  together  in  the  form  of  an 
inclosed  cylinder,  in  length  about  two  and  one-half  times 
greater  than  the  diameter,  and  are  furnished  with  dia- 
phragms or  false  bottoms.  The  drawing.  Fig.  2,  is  very  ex- 
plicit, and  the  mode  of  working  these  machines,  and  the  use 
and  application  of  their  various  appointments  will  be  men- 
tioned in  reciting  the  process  as  practically  carried  through 
in  the  laboratory  of  the  inventor.  It  is  as  follows :  The  false 
bottom  being  arranged  in  its  place,  and  the  discharging  hole 
closed  up,  the  steam-tight  iron  tank  or  cylinder  is  filled 
through  the  man-hole  with  the  rough  lard  material,  to  with- 
in about  two  and  a  half  feet  of  the  top.  This  d(me,  the  man- 
l)late  K  is  securely  fitted  into  the  man-hole  H,  and  steam  let 
on  from  an  ordinary  steam  boiler,  through  the  foot  valve, 
into  the  perforated  pipe  C  within  the  tank.  Set  the  w^eight 
on  the  valve  at  the  requisite  [)ressure,  and  during  the  steam- 
ing, frequently  and  carefully  assay  as  to  the  state  of  the  con- 
tents of  the  tank  by  opening  the  try-cock  R.   If  the  quantity 


MATERIALS  USED  IN  THE  JVIANUFACTURE  OF  SOAPS.  89 


of  condensed  steam  in  the  tank  is  too  great,  it  will  be  indi- 
cated by  the  ejection  of  the  fatty  contents  in  a  spurt.  In 
such  a  case  it  is  then  requisite  immediately  to  open  the  regu- 
lating  cock  X  and  draw  off  the  condensed  steam,  through  it, 
into  the  receiving  tub  T,  until  the  fatty  matter  ceases  to  run 
from  the  try-cock  aforesaid.  After  ten  or  fifteen  hours' 
continued  ebullition,  the  steam  is  stopped  oft",  and  that  excess 
already  in  and  uncondensed,  allowed  to  escape  through  the 
try-cock  and  safety-valve.  After  sufficient  repose,  the  fatty 
matter  separates  entirely  from  water  and  foreign  admixture, 
and  forms  the  upper  stratum.  It  is  drawn  off  through  the 
cocks  jpp  in  the  side  of  the  tank,  into  coolers  of  ordinary 
construction.  The  tank  being  emptied  of  its  lard  contents, 
the  cover  F  is  raised  by  means  of  the  rod  G,  from  the  dis- 
charging hole  E,  and  the  residual  matters  at  the  bottom  let 
out  into  the  tub  T.  If,  on  inspection,  the  contents  of  this 
tub  have  retained  any  fat,  it  must  be  again  returned  to 
the  tanks,  when  they  are  being  filled  for  a  fresh  operation. 
Experience  has  determined  that,  to  produce  the  best  result, 
the  steam  pressure  should  be  not  less  than  fifty  pounds  to  the 
square  inch,  though  that  often  used  is  seventy-five  pounds, 
and  may  be  augmented  to  one  hundred  pounds  when  it 
is  desired  to  expedite  the  operation.  We  should,  however, 
advise  against  so  high  a  pressure  in  the  preparation  of 
tallow;  it  may  do  well  enough  for  lard  ;  but  if  these  closed 
tanks  are  made  to  operate  as  digesters,  the  efiect  produced 
by  the  decomposition  of  bones  and  other  matters,  which, 
in  the  wholesale  way  of  preparing  fats  at  the  West,  are 
generally  thrown  in  indiscriminately  with  the  rough  suet, 
would  be  to  deteriorate  its  quality.  The  better  way  is  to 
take  a  little  more  time,  and  thus  insure  a  better  result.  The 
process  is  sufiiciently  economical  as  it  is,  for,  wiiilst  by  a  pres- 
sure of  between  fifty  and  seventy  pounds,  the  bones,  etc.,  are 
made  to  yield  all  their  oleaginous  or  fatty  matter,  there  is  no 
action  occasioned  whicli  will  convert  them  into  an  offensive 
constituent.  In  making  lard  from  the  w^hole  carcass  of  the 
hog,  excepting  the  hams  and  shoulders,  a  yield  is  always 
obtained,  by  the  use  of  this  apparatus,  full  twelve  per  cent. 


90 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


greater  than  by  any  other  methods  ;  whilst  in  rendering  tal- 
low, the  gain  exceeds  the  product  furnished  by  the  ordinary 
plans  at  least  six  per  cent.  To  say  nothing  of  the  economy 
both  of  time  and  labor  (fifty  per  cent,  of  each),  the  material 
obtained  is  so  much  superior,  that  it  always  commands,  if 
not  the  preference,  at  least  a  slight  advance  of  price,  in  the 
market.  The  marc  or  residuum,  thrown  out  into  the  tub  T, 
being  rich  in  nitrogenous  and  phosphated  matter,  when  dried 
and  mixed  with  bog  or  street  earth,  and  gypsum,  makes 
manure  equalling  the  best  guano. 

Proper  management  of  the  apparatus  will  generally  pre- 
vent any  escape  of  the  offensive  vapors  incident  to  the  ope- 
ration ;  but  occasionally  leaks  will  occur  at  the  valve.  The 
condensed  steam  carries  down  all  the  impurities  of  the  fat, 
and  leaves  it  clean  and  white.  Moreover,  it  is  firm  if  rapidly 
cooled  in  vessels  of  small  capacitj^,  for  the  temperatures  of 
large  volumes  fall  so  slowly,  that  partial  granulation  ensues 
and  softens  its  consistency. 

With  all  these  advantages,  however,  this  process  is  not 
wholly  faultless  ;  for  the  difficulty  of  separating  all  the  water 
slightly  endangers  the  purity  of  the  fat,  as  the  former  intro- 
duces, in  solution,  a  portion  of  animal  matter,  which,  in  time, 
becomes  putrescent,  and  imparts  an  offensive  smell  to  the 
latter.  Repeated  washing  of  the  fat  with  fresh  water,  and 
careful  remelting  and  settling,  would  remedy  this  defect  in 
a  great  measure. 

Butter 

finds  but  little  application  in  the  manufacture  of  soap,  on 
account  of  its  cost,  though  if  it  were  less  costly  it  would 
prove  a  very  advantageous  material  particularly  for  toilet 
soaps,  as  soap  made  wnth  it  is  of  beautiful  consistency  and 
appearance,  and  it  is  subject  to  less  loss  in  saponification  than 
most  other  fatty  bodies. 

Butter  is  the  fatty  substance  with  which  the  globules  of 
milk  are  formed.  These  globules  do  not  freely  float  in  this 
liquid  ;  they  are  surrounded  by  a  very  thin  membrane,  which 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  91 

prevents  them  from  joininoj  together.  When,  by  any  pro- 
cess, they  can  be  united,  butter  is  formed.  A  butter  well 
prepared  must  be  of  a  fine  yellow  color,  of  a  middling  con- 
sistency, with  a  peculiar  and  slightly  aromatic  odor,  and  an 
agreeable  taste.    It  must  be  easy  to  cut  into  slices. 

The  composition  of  butter  seems  to  be  very  complex.  M. 
Chevreul  has  demonstrated  that  this  body  contains  five  neu- 
tral substances,  which  are,  olein^  margarin^  butyrin^  caprin^ 
and  caproin.  These  fatty  bodies,  treated  by  alkalies,  are 
saponified  and  transformed  into  oleic,  margaric,  butyric,  cap- 
ric,  and  caproic  acids ;  the  last  three  are  volatile,  and  can  be 
separated  from  the  two  others  by  distillation. 

According  to  Heintz,  butter  contains  ordinarily  olein, 
much  palmitin,  a  little  stearin,  and  small  quantities  of  neu- 
tral bodies  giving  by  saponification  myristic  and  butyric 
acids. 

Butter  dissolves  in  28  parts  of  boiling  alcohol  at  35°  C. 
(95°  F.);  it  melts  at  36°  C.  (96.8°  F.).  It  becomes  rancid 
very  easily;  this  alteration  can  be  prevented  by  salting  or 
melting  it. 

Butter  washed  with  warm  water,  cooled  and  pressed  yields, 
by  successive  crystallizations  in  a  mixture  of  alcohol  and 
ether,  a  substance  melting  at  48°  C.  (118.4°  F.),  which  presents 
the  characteristics  of  margarin.  The  liquid  fatty  body  ex- 
tracted from  butter  by  pressure  is  almost  entirely  formed  of 
a  substance  different  from  olein,  and  is  transformed  by  saponi- 
fication into  glyceryl  oxide  and  a  new  acid,  oleo-huiyric  acid. 

The  relative  proportions  of  the  immediate  principles  of 
butter  vary  under  different  circumstances;  however,  the  fol- 
lowing composition  has  been  assigned  to  it : — 

Margarin     .  68 

Butyrolein  30 


Butyri 


3 


92 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Bone  Fat 

The  grease  contained  in  the  bones  of  the  sheep  and  the  ox 
is  a  very  useful  material  for  soap,  saponifying  in  the  same 
manner  as  tallow,  though  making  a  softer  soap,  its  melting- 
point  being  much  lower.  It  usually  contains  many  impuri- 
ties ;  that  extracted  from  fresh  bones  finds  application  as  a 
very  fine  lubricator  for  machinery. 

To  produce  this  fat,  the  bones  are  broken,  as  much  as  pos- 
sible in  a  lengthwise  direction.  Where  large  quantities  are 
worked  up — as  in  bone-kilns  — they  are  crushed  by  passing 
them  through  iron  rollers.  The  crushed  bones  are  then  put 
into  a  kettle,  partly  tilled  with  water,  and  heated  to  the  boil- 
ing point,  which  causes  the  fat  to  float  on  the  surface,  where 
it  is  skimmed  off  with  a  flat  iron-spoon  and  passed  through 
a  sieve,  which  retains  the  solid  particles.  When  it  is  noticed 
that  no  more  fat  separates,  the  bones  are  taken  out,  by  means 
of  a  large  perforated  shovel,  and  replaced  by  fresh  ones,  so 
that  the  water  may  be  used  several  times. 

The  fat  thus  obtained  is  generally  of  a  brownish  color  and 
of  an  unpleasant  odor,  and  when  cooled  oft',  congeals  to  a 
grainy,  smeary  consistency,  and  retains  some  water,  which 
may  be  separated  by  remelting  and  settling. 

The  soda  soap  made  with  bone  fat  is  not  very  solid,  but  with 
a  suitable  quantity  of  linseed  or  hempseed  oil  and  potash  lye 
a  soft  soap  is  made,  which  after  some  little  time  shows  a 
very  fine  so-called  natural  grain  derived  from  the  crystallized 
stearic  and  palmitic  acid  potash  soap. 

In  several  places  still  another  kind  of  bone  fat  is  yielded, 
in  the  process  of  making  glue.  This  fat  is  at  the  ordinary 
temperature  liquid  like  oil,  and  has  a  dark  brown  color, 
which,  however,  does  not  pass  over  into  the  soaps  boiled 
therein,  but  by  salting  passes  down  into  the  sub-lyes,  so  that  a 
nearly  white  soap  is  yielded,  which  is  not  very  hard.  Hence 
it  is  customary  to  mix  it  with  other  fats,  palm  oil,  tallow,  etc. 
This  fat  often  contains  from  two  to  three  per  cent,  of  lime, 
most  likely  lactic  acid  lime,  which  is  soluble  in  fat  oils. 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  93 


This  lime  causes  the  fats  boiled  in  the  soda  lyes  to  become 
spongy,  and  can  only  be  separated  by  adding  culinary  salt, 
and  then  with  difficulty.  To  avoid  these  troubles,  the  lime 
should  be  separated,  which  can  very  easily  be  done  if  the  fat 
is  worked  with  a  sufficient  quantity  of  water  containing  sul- 
phuric or  muriatic  acid.  Whether  or  not  such  a  fat  contains 
lime,  can  be  ascertained,  if  a  sample  thereof  is  mixed  with 
a  solution  of  oxalic  acid  and  well  stirred.  If  lime  be  pre- 
sent there  appears  after  a  little  while  a  liquid,  which  be- 
comes muddy  by  the  formation  of  oxalate  of  lime ;  in  the 
other  case  the  water  which  is  under  the  oil  appears,  after 
separating  from  the  oil,  entirely  clear. 

Horse  Fat. 

This  fatty  body,  though  repulsive  on  account  of  the  care- 
less manner  in  which  it  is  prepared  from  the  carcass,  is  yet, 
when  extracted  from  the  recently  slaughtered  animal,  a 
very  suitable  and  good  material  for  the  manufacture  of  com- 
mon soap,  the  product  with  soda  lye  being  white  and  of  good 
consistency. 

The  appearance  of  this  fat  varies  according  to  the  organs 
from  which  it  is  taken,  and  the  care  given  to  its  production. 
It  is  either  solid,  forming  a  real  tallow,  or  it  is  more  or  less 
of  the  consistency  of  lard,  and  is  generally  of  a  dirty-white 
color. 

The  horse  fat  which  appears  in  commerce,  and  which 
comes  from  slaughtered  horses,  and  appears  to  be  produced 
with  more  care,  of  course  deserves  in  many  respects  the  pre- 
ference. It  is  almost  odorless,  of  a  yellowish  tinge,  of  the 
consistency  of  butter,  and  yields  just  as  white  and  solid  soap 
as  pure  tallow  or  bleached  palm  oil,  and  does  not  impart 
to  the  clothes  washed  therewith  that  disagreeable  smell 
which  they  acquire  from  the  common  horse  fat  soap. 

Glue  Fat. 

In  making  glue  from  hides,  tendons,  etc.,  much  fat  is  col- 
lected which  if  well  prepared  can  be  usefully  employed  in 


94 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


making  soap.  As  found  in  commerce  glue  fat  contains  a 
large  amount  of  lime  and  other  impurities,  which  can,  how- 
ever, be  extracted  with  dilute  sulphuric  acid.  When  the  fat  is 
boiled  in  a  live  per  cent,  solution  of  sulphuric  acid  for  about 
an  hour,  the  lime  and  other  impurities  are  carried  down  with 
the  water,  the  clear  grease  floating  on  the  surface  whence  it 
can  be  ladled  off.  This  sebacic  acid  will  then  make  with 
soda  Ije  with  or  without  rosin  a  good  and  firm  soap,  useful 
for  all  domestic  purposes.  It  should  be  boiled,  for  in  the 
Swiss  or  cold  soaps  it  would  not  answer  so  well. 

Neat's  Foot  Oil. 

If  this  product  were  abundant  it  could  be  usefully  applied 
in  making  soaps  of  good  quality,  but  it  is  generally  used  for 
dressing  leather,  for  which  it  is  admirably  adapted.  It  is 
prepared  by  boiling  in  water  the  feet  of  cattle  deprived  of 
flesh  and  sinews,  and  removing  the  grease  which  floats  upon 
the  surface.  It  is  of  a  greenish-yellow  color,  and  if  fresh  has 
no  odor,  is  limpid  at  ordinary  temperatures,  becoming  solid 
in  the  cold.  It  forms  w^ith  soda  lye  a  very  fine  white  soap 
partaking  of  the  nature  of  the  fat,  being  somewhat  soft, 
olein  being  the  largest  constituent  of  the  oil. 

Kitchen  Fat. 

The  refuse  fat  of  families,  hotels,  restaurants,  etc.,  finds  a 
very  useful  purpose  in  soap  manufacture,  and  when  it  is  sys- 
tematically collected  and  properly  purified  becomes  of  much 
value.  It  is,  however,  often  of  inferior  quality,  being  soft, 
green,  and  limpid,  and  in  this  state  is  termed  weak  stock. 
In  this  condition  it  may  be  much  improved  by  boiling  with 
salt  and  alum,  but  a  much  better  mode  would  be  the  purifi- 
cation with  dilute  sulphuric  acid,  a  process  often  mentioned 
in  this  treatise. 

We  deem  the  utilization  of  this  and  other  refuse  greases 
and  fats  of  so  much  importance  that  w^e  shall  give  a  special 
section  more  fully  explaining  it. 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  95 


Fish  Oils. 

In  this  category  are  classed  the  oils  from  a  very  numerous 
variety  of  animals  many  of  which  are  not,  strictly  speaking, 
fishes.  The  oils  of  commerce  are  extracted  from  whales, 
seals,  porpoises,  and  many  kinds  of  fishes,  and  are  almost 
always  designated  by  the  name  of  the  source,  as  whale,  seal, 
cod-liver  oil,  etc.  Many  called  train  oils  are  extracted  from 
the  seal,  herring,  etc. 

Train  oil  has  a  specific  gravity  of  0.925  to  0.930,  and  is 
principally  composed  of  common  olein  with  palmitin.  Its 
peculiar  smell  originates  from  valerianic  acid,  glyceryl 
oxide,  and  a  substance  which  is  considered  to  be  a  combina- 
tion of  a  special  acid,  viz.,  dolphic  or  phocenic  acid,  with 
glyceryl  oxide. 

Various  means  are  applied  in  purifying  the  bad  smelling 
and  dark  colored  train  oils.  Shaking  with  milk  of  lime, 
with  diluted  potash  or  soda  lye,  culinary  salt,  and  copperas  is 
common,  as  well  as  filtering  with  wood  ashes.  According  to 
Davidson,  train  oil  should  be  shaken  with  a  decoction  made  of 
oak  bark,  then  have  mixed  with  it  4  parts  of  chloride  of  lime 
(bleaching  powder)  stirred  into  12  parts  of  water,  permitting 
it  to  clear  ofi',  when  a  thick  whitish  mass  will  be  separated, 
and  add  diluted  sulphuric  acid  to  settle  the  lime  which  be- 
comes free.  We  are  convinced,  by  experiments  which  we 
have  made  on  a  large  scale,  that  this  means  is  by  far  the  best 
of  all  those  used  for  disinfecting,  since  train  oil  loses  by 
this  treatment  the  greater  part  of  its  disgusting  smell,  so 
that  such  train  oil  unsaponified  appears  almost  odorless.  But 
nevertheless  the  smell  reappears  when  the  train  oil  is  changed 
into  soap.  Hence  train  oil  can  only  be  used  in  manufacturing 
very  common  soaps,  or  by  mixing  small  quantities  of  it  with 
other  fats. 

Cod-liver  Oil 

is  obtained  from  three  species  of  fish,  viz.,  from  the  torsk 
{Gadus  callarias)^  the  say  {Gadus  carbonarius),  and  the  shark 


96 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


{Gadus  poUackhis) ;  in  France,  according  to  Gobeley,  from 
the  livers  of  Baja  batis  and  Raja  cavata.  It  has  been  proposed 
.to  term  the  first  sorts  Morrhua  oil,  and  the  latter  Raja  oil. 
The  shark  livers  furnish  the  oil  but  slowly  ;  they  must  there- 
fore be  cut  up  into  pieces  and  boiled  down.  The  say  livers, 
as  well  as  the  torsk  livers,  w^hen  thrown  into  water  have  a 
great  portion  of  their  oil  to  flow  out  spontaneously ;  that  of 
the  latter  is  a  thinner  liquid  but  somewhat  darker,  while 
that  of  the  former  is  lighter  but  of  a  thicker  consistency. 
All  livers  are  finally  boiled  down,  and  furnish  ordinarily  the  - 
common  cod-liver  oil,  which,  however,  never  possesses  the 
disao-reeable  smell  of  common  train  oil. 

The  main  bulk  of  cod-liver  oil  is  likewise  composed  of 
palmitic  acid  (11  to  16  per  cent.), oleic  acid  (70  to  74  per  cent.), 
and  glycerine  (9  per  cent.) ;  furthermore  of  a  peculiar  sub- 
stance, called  gadidn,  a  body  of  the  nature  of  a  weak  acid, 
small  portions  of  lactic  acetic  acid,  valerianic  acid,  gall 
substances,  iodine,  phosphorus,  sulphur,  traces  of  bromine  and 
inorganic  salts.  By  shaking  up  with  water  the  dark  cod- 
liver  oil  becomes  somewhat  lighter,  since  a  part  of  the  pig- 
ment substances  are  dissolved.  Diluted  sulphuric  acid  causes 
the  separation  of  brownish  flakes ;  concentrated  sul[)huric 
acid  causes  the  train  oil  to  become  of  a  brown  color. 

Train  oil  has  the  property  of  dissolving  large  quantities  of 
colophony,  without  thereby  changing  its  consistency,  i,  e.,  not 
becoming  a  thicker  liquid.  Rosin  being  usually  much  cheaper 
than  train  oil,  this  peculiarity  has  been  utilized  for  the  pur- 
pose of  adulterating  it.  Such  an  adulteration  is,  however,  ^ 
easily  detected  by  placing  the  suspected  train  oil  in  a  flask 
with  an  equal  volume  of  alcohol,  and  shaking  it,  when  the 
rosin  will  be  completely  dissolved.  When  left  to  settle, 
both  liquids  separate  into  two  layers,  of  which  the  lower  is 
the  train  oil.  By  kee[»ing  a  record  of  its  original  volume 
we  may  conclude  how^  large  a  quantity  of  rosin  had  been 
added,  making  an  allowance  for  a  small  portion  which  had 
been  dissolved  in  the  alcohol. 

Sometimes  the  fat  of  sahno-phymallus^  known  under  the 
name  of  ash-fat^  is  brought  into  commerce  in  place  of  train 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  97 


oil.  It  is  a  mild  yellow  oil,  which  has  a  weak  fishy  smell,  and 
is  for  making  soap  no  less  applicable  than  train  oil. 


The  vegetable  oils  applied  to  the  manufacture  of  soaps  are 
very  numerous  and  valuable,  and  are  found  in  the  fruits, 
seeds,  etc.,  of  plants.  They  are  usually  termed  fixed  oils, 
and  are  generally  limpid  at  ordinary  temperatures;  some, 
however,  have  more  or  less  consistency,  containing  palmitin, 
stearin,  etc.,  combined  with  the  olein.  All  have  a  specific 
gravity  less  than  water,  or  about  0.920. 

We  append  tables  of  the  usual  vegetable  fatty  bodies  em- 
ployed in  making  soa}>,  with  their  sources  of  production  and 
their  j\e\d  from  the  seeds,  etc. : — 


Oils  and  Fats  of  Yegetablk  Origin. 


Fixed  oils. 

Olive  oil  . 
Groundnut  oil  . 
Hempseed  oil  . 
Almond  oil 
Coleseed  oil 
Rapeseed  oil 
Cocoanut  oil 
Cotton-seed  oil. 
Beechnut  oil 
Cocoa  butter 
Hazel-nut  oil 
Poppy  oil  . 
Ben  oil 
Laurel  oil  . 
Linseed  oil 
Castor  oil  . 
Camelina  oil 
Nut  oil 

Sunflower-seed  oil 
Sesamum  oil 
Pitch-tree  oil  . 
Pine  oil 


egetables  which  produce  them. 

Olea  Europaea. 

Arachis  hypogaea. 

Cannabis  sativa. 
,    Amygdalus  communis. 
,    Brassica  oleracea. 

Brassica  napus. 

Cocos  nucifera. 

Gossypium  hcrbaceum. 

Fagus  sylvatica. 
.    Theobroma  cacao. 

Corylus  avellana. 

Papaver  somniferum. 

Guilandina  morinffa. 

Laurus  nobilis. 

Linum  usltatissimum. 

Kicinus  communis. 

Myagrum  sativum. 

Juglans  regia. 

Helianthus  annuus. 

Sesamum  orientale. 

Pinus  abies. 

Pinus  sylvestris. 


Etc. 


etc. 


The  following  table  gives  the  quantities  of  oils  which  may 
be  extracted  from  the  vegetables: — 
7 


98  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


100  parts  in  weight. 

Oil  extracted. 

10)  parts  in  weight. 

Oil  extracted. 

Nut     ...  . 

40  to  70 

Euphorbium 

30 

Castor  .       .       .  . 

62 

Wild  mustard 

30 

Hazel-nut 

60 

Camelina 

28 

Cress    .       .       .  . 

56  to  58 

Woad  .       .       .  . 

29  to  36 

Sweet  almonds  . 

40  to  54 

Gourd  .       .       .  . 

25 

Bitter  " 

28  to  46 

Lemon -tree  . 

25 

Black  garden  poppy  . 

56  to  63 

Onoporde  acanthe 

25 

Radishes 

50 

Epicea  seeds 

24 

Sesamum 

50 

Hempseed  . 

14  to  25 

Linden 

48 

Linseed 

20  to  30 

Earth-nut 

43 

Black  mustard 

1.5 

Cabbage 

30  to  39 

Beech  .       .       .  . 

15  to  20 

White  mustard 

36  to  38 

Sunflower  seed 

25 

Turnip .... 

33.5 

Apples  .       .       .  . 

15 

Plum    .       .       .  . 

33.5 

Grapestone  . 

14  to  22 

Coleseed 

36  to  40 

Horsechestnut 

8 

Rapeseed 

35  to  40 

Olive    .       .       .  . 

12  to  20 

Cotton-seed  . 

20 

Physical  Pro'pprties 

of  Oils.- 

-Fixed  oils,  at  the 

ordinary 

tem[ierature,  are  nearly  always  liquid  ;  some  however,  such 
as  palm  oil,  cocoanut  oil,  etc.,  are  more  or  less  consistent. 
They  are  also  more  or  less  mucilaginous,  with  a  feeble  taste, 
sometimes  disagreeable.  Some  are  colorless,  but  generally 
they  have  a  sight  yellow  tint;  some  are  of  a  greenish-yellow 
color,  and  this  color  is  due  to  a  peculiar  principle  they  hold 
in  solution.  Their  sjiecific  gravity  is  le>s  than  that  of  water, 
all  floating  on  this  liquid,  but  it  varies. 

Olive  Oil 

is  perhaps  the  oldest  known  and  used  for  the  purpose  of 
making  fine  soaps,  and  possesses  all  the  best  characteristics 
for  the  purpose,  making  a  firm  white  soap  having  an  agree- 
able odor.  At  ordinary  temperatures  it  is  fluid,  but  at  a 
low  degree  of  heat  it  congeals,  the  stearin  crystallizing.  It 
consists  of  about  seventy-five  per  cent,  of  olein  with  twenty- 
five  per  cent,  of  stearin. 

Olive  oil  being  consumed  as  food  in  large  quantities,  there 
is  much  care  taken  to  produce  a  fine  quality  for  this  purpose, 
and  the  best  of  the  first  and  second  pressing  is  usually  re- 
served for  table  use.    It  is  obtained  from  the  ripe  olives  by 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  99 


submitting  the  crushed  fruit  to  a  pressure  either  between 
warmed  iron  phites,  or  heating  the  mass  slightly,  before  put- 
tino;  it  into  the  bao^s.  The  first  oil  is  called  viro^in  oil.  The 
marc,  being  again  steamed  or  heated,  is  submitted  to  the  press 
a  second  time;  this  product  is  still  a  very  good  oil.  At  the 
third  pressing  the  marc  is  often  mixed  with  hot  water,  and 
when  it  is  pressed  the  oil  runs  out  combined  with  the  water 
and  some  albumen  and  floats  upon  the  surface,  whence  it  is 
skimmed  off.  For  an  inferior  oil  the  marc  is  thrown  into 
vatsand  allowed  to  ferment ;  the  remaining  oil  being  liberated 
floats  on  the  surface.  This  last  oil  i;*  usually  mu(;h  colored 
and  of  unpleasant  odor,  but  it  is  the  oil  usually  applied  in 
making  soap.  The  resulting  soap  does  not  retain  either 
color  or  odor,  but  is  white  and  sweet. 

The  oil  of  manufacture,  or  huile  (Vir^fer^  as  the  common 
oil  is  termed,  is  consumed  in  large  quantities  at  Marseilles 
and  elsewhere,  to  the  amount  of  nearly  four  million  gallons 
per  annum,  principally  in  manufacturing  the  Marseilles  or 
castile  soap,  and,  owing  to  its  great  value,  it  is  the  subject 
of  much  adulteration  with  other  bland  or  sweet  oils,  princi- 
ply  nut  oil,  sesame  oil,  j>opjty  oil,  aiid  cotton-seed  oil.  The 
detection  of  these  sophistications  is  quite  a  difficult  matter, 
although  we  give  elsewhere  some  directions  for  that  pur|)Ose. 

Olive  oil,  though  making  some  of  the  best  soaps  known  to 
commerce,  is  now  seldom  used  alone,  the  soap  becoming 
when  dry  too  hard  for  general  purposes.  It  is  now  customary 
to  add  to  it  a  certain  quantity  of  hemp-seed,  rape-seed, 
poppy-seed,  or  ground-nut  oil,  these  oils  being  slightly  dry- 
ing oils  and  producing  a  softer  soap,  qualify  the  olive-oil 
soap  in  its  consistency. 

Palm  Oil 

may  be  considered  next  in  importance  to  olive  oil  in  the 
fabrication  of  soap,  for  which  purpose  it  is  consumed  in  vast 
quantities,  in  England  especially,  where  it  was  first  used.  It 
enters  into  nearly  all  their  best  rosin  soaps,  and  this  admix- 
ture has  given  both  character  and  popularity  to  English 


100  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


yellow  soaps.  It  is  also  used  advantageously  in  many  soaps 
for  toilet  purposes. 

It  is  obtained  from  the  fruit  of  a  species  of  palm,  the  Avoira 
Mais  or  JElais  guianensis  ;  according  to  others,  however,  from 
Cocus  biitf/raeea,  as  well  as  from  an  areca  species.  It  is,  how- 
ever, not  improbable,  that  all  these  plants  produce  similar 
vegetable  oils.  Palm  oil  is  a  [)roduct  of  the  soil  of  tropical 
Africa  and  South  America  (Guiana);  the  Canary  Islands, 
and  also  of  some  other  regions.  Owing  to  its  general  ap- 
].)lication  in  manufacturing  soMp  it  has  become  a  very  im- 
portant article  of  commerce,  a  place  to  which  it  was  as- 
signed by  dint  of  a  renmrkable  connection  of  circumstances, 
and  by  the  endeavors  of  the  English  government  in  the 
suppression  of  the  slave  trade.  Since  this  traffic,  by  the 
measures  taken  against  it  by  Etigland — if  not  yet  entirely 
suppressed — is  much  limited,  the  natives  of  those  coast  dis- 
tricts are  compelled,  in  lieu  of  as  heretofore  trading  in  human 
beings,  to  pay  for  their  necessary  commodities,  at  this  day, 
with  some  of  the  useful  products  of  the  African  soil,  includ- 
ing palm  oil.  The  largest  consumption  of  palm  oil  is  in 
England,  which  country,  in  1879,  imported  147,993,216  lbs., 
but  the  consumption  of  it  is  also  very  great  in  Germany, 
France,  and  the  United  States.  The  ditJerent  kinds  in  the 
market  have  various  names;  the  prima  logos  and  secunda 
lagos  being  the  most  excellent ;  the  former  can  be  more  easily 
bleached  than  the  latter. 

The  fruits  of  these  palms  are  of  the  s^ze  and  dimension  of 
a  pigeon's  egg,  and  contain  a  solid  kernel  under  a  fleshy 
cover.  The  pain]  oil  is  extracted  from  this  latter,  not  from 
the  kernel.  For  this  purpose  the  pared  flesh  is  boiled  out 
in  water,  when  the  oil  collects  on  the  surface  in  a  fluid  state, 
and  can  easily  be  skimmed  oflf.  After  cooling  off  it  forms  a 
reddish-yellowy  fat  of  the  consistency  of  butter,  which  melts 
at  29°  C.  (84.2°  F.).  Since  the  word  oil  is  applied  to  desig- 
nate the  liquid  fiUs,  the  name  of  i)alm  oil  is  an  improper  one  ; 
palm  butter  would  be  more  correct.  Its  smell  is  strong,  but 
agreeably  aromatic,  and  reminds  one  of  orris  root.  As  it  ap- 
pears in  commerce,  the  palm  oil  is  always  more  or  less  rancid, 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  101 


e.  I.,  it  contains  free  sebacic  acids,  instead  of  being  in  the 
fresh  state  neutral  with  glyceryl  oxide.  The  quantity 
of  these  free  acids  increases  with  age,  and  at  the  same 
time  the  melting-point  rises:  the  dark  orange-red  color 
changing  into  lemon-yellow.  Pelouze  and  Bendot  found  in 
fresh  palm  oil  one-third,  in  that  which  melted  at  31°  C. 
(87.8°  F.)  (me-half,  in  another  sample,  which  melted  at  36° 
C.  (96.8°  F.),  four-fifths  of  its  weight  in  free  acid.  In 
very  old  palm  oil,  Stenhouse  found  the  melting-point  37°  C. 
(98.6°  F.). 

From  the  tests  made  by  Fremy  and  the  above-mentioned 
chemists  it  was  o^leaned  that  this  veiretable  fat  contains  free 
oleic  acid,  a  specific  sebacic  acid,  palmitic  acid,  and  some 
palmitin,  e.i.,  palmitic  acid  oxide  of  glyceryl.  The  latter  can 
be  obtained  by  pressing  the  palm  oil  at  10°  to  12°  C.  (50°  to 
53.6°  F.),  and  a  second  time  at  about  20°  C.  (68°  F.)  in  large 
quantities,  as  a  wax-like  white  mass,  of  which  a  sort  of 
stearin  candles  can  be  njade,  while  the  yellow  oil  that  flows 
oft*  may  be  made  into  soap. 

Since  the  reddish-yellow  color  of  the  palm  oil  is  not  de- 
stroyed during  saponification,  but  remains  in  the  soap,  the  oil 
must,  if  w4iite  soaps  are  to  be  manufactured,  first  be  bleached. 
This  is  done,  either  by  means  of  oxides,  as  muriatic  acid, 
nitric  acid,  sulphuric  acid,  etc.,  alone  or  with  permanganate 
or  chromate  of  potassa,  or  by  heating  the  palm  oil  to  a  certain 
degree.  In  all  these  cases  the  color  will  be  more  or  less  com- 
pletely destroyed,  without  reappearing  in  the  soap.  It  must, 
however,  be  observed,  that  the  bleaching  by  means  of  oxida- 
tion generally,  especially  with  sulphuric  acid  and  chromate 
of  potash,  furnishes  a  better  and  a  whiter  oil,  and  is  more 
easily  accomplished,  although  more  expensive,  than  the 
bleaching  bj^  heat.  The  latter  requires,  moreover,  more  at- 
tention in  the  managing  of  the  process,  and  a  greater  loss 
(from  three  to  four  and  a  half  per  cent.)  is  entailed,  than  by 
the  first  method. 

For  the  bleaching  of  palm  oil  by  means  of  bichromate  of 
potassa,  a  quantit}^  of  palm  oil  is  melted  at  60°  C.  (140°  F.), 
and  left  standing  over-night,  so  that  all  impurities  may 


102 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


settle  upon  the  bottom.  On  the  day  following,  the  clear  oil 
is  placed  in  a  clean  barrel  and  allowed  to  cool  off  to  40°  to 
38°  C.  (104°  to  100.4°  F.).  At  the  same  time  a  portion  of 
water  is  heated  to  the  boiling-point,  and  in  this  is  dissolved 
a  suitable  quatitity  of  bichromate  of  potnssa.  If  for  instance 
1000  kilogrammes  (2200  lbs.)  of  palm  oil  are  to  be  worked, 
45  kilogrammes  (99  lbs.)  of  water  are  taken,  and  15  kilo- 
grammes (33  ll>s.)  of  the  bichromate  of  potassa  are  dissolved 
therein.  After  the  solution  has  cooled  oft'  somewhat,  pour 
in  60  kilogrammes  (132  lbs.)  commercial  muriatic  acid.  This 
mixture  of  chromic  acid  salt  solution  and  muriatic  acid  is 
now  poured  into  the  palm  oil,  which  during  this  process  is 
being  well  stirred.  After  a  period  of  tive  minutes,  the  oil 
becomes  dark-green,  by  separation  of  chromate  or  by  for- 
mation of  chrom-chloride,  which  by  a  continuation  of  the 
stirring  entirely  separates,  or  is  retained  by  the  water  in 
solution.  Should  the  oil  not  yet  be  sufticiently  bleached,  the 
operation  should  be  repeated  by  using  I  kilogramme  (8.8  ozs.) 
bichromate  of  potassa  and  1  kilogramme  (2.2  lbs)  muriatic 
acid,  as  before. 

The  bleaching  of  palm  oil  by  the  application  of  heat  is 
more  simple,  but  does  not  readily  furnish  such  a  clear  oil  as 
is  required  for  some  soaps.  Here  two  things  have  to  be  ob- 
served :  first,  that  the  heat  is  not  too  much  increased,  be- 
cause the  oil  might  assume  a  disagreeable  brownish  color, 
which  appears  in  the  soap;  secondly,  that  the  oil  is  previ- 
ously melted  upon  water,  or  at  least  melted  at  a  moderate 
heat,  and  left  to  rest  for  a  short  time,  and  poured  oft*  as  clear 
of  all  sediment  as  possible.  If  the  latter,  consisting  espe- 
cially of  small  pieces  of  fruit  and  of  small  imperfect  fruits,  is 
heated  with  the  oils  which  are  to  be  bleached,  a  good  oil  is 
never  obtained.  The  temperature  which  is  applied  in  this 
case  varies,  and  some  operators  go  as  high  as  160°  C.  (320° 
F.);  but  it  is  found  that  [)alm  oil  can  be  bleached  thoroughly 
at  120°  C.  (248°  F.),  or  as  much  as  is  possible  by  the  process 
of  heating.  The  contact  of  the  air  accelerates  the  process  of 
bleaching;  and  palm  oil  is  bleached  the  fastest  and  best  in 
a  kettle  which  is  covered  with  a  well-fitting  lid,  in  which 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  103 


an  iron  pipe  of  7|  to  10  centimetres  (2.9  to  3.93  inches)  thick- 
ness is  inserted,  which  opens  in  the  chimney  of  the  fire  space, 
of  the  kettle  similar  to  the  apparatus  used  hy  Grodhaus  and 
Fink  or  Yohl,  elsewhere  illustrated,  for  the  removal  of  the 
fetid  vapors  in  the  pn^cess  of  rendering  old  tallow.  This 
has  at  the  same  time  the  advantage,  that  the  sharp  poignant 
smelling  vapors  are  removed  without  any  danger  whatever, 
since  it  is  performed  at  the  lowest  possible  temperature  with- 
out the  oil  becoming  in  the  least  brown,  and  the  process  is 
finished  in  from  three  to  ten  hours,  according  to  the  quantity. 
It  is  generally  i)referable  not  to  bleach  too  large  quantities  at 
once,  indeed  there  is  rarely  a  saving  of  time;  since  a  portion 
of  400  kilogrammes  (880  lbs.)  bleaches  in  four  separate  por- 
tions, /.  6'.,  each  time  100  kilogrammes  (220  lbs.)  easier  and 
better  than  when  all  is  taken  at  once. 

The  finishing  of  the  bleaching  process  is  best  ascertained 
by  placing  from  time  to  time  a  few  drops  of  the  oil  upon  a 
porcelain  plate,  and  thus  comparing  their  color.  As  soon  as 
it  is  observed  that  the  succeeding  drops  are  no  longer  of  a 
difierent  shade  of  color  than  those  preceding,  the  operation 
is  considered  finished. 

In  cooling  ofi'  the  bleached  oil,  great  care  must  be  taken 
in  adding  water  to  it,  for  if  it  is  not  performed  with  the 
greatest  care,  an  explosion  may  ensue.  It  is  niore  judicious 
to  add  a  portion  of  formerly  bleached  cold  oil,  until  the  tem- 
perature has  sunk  below  100°  C.  (212°  F.),  when,  without  the 
least  danger,  water  may  be  added  to  hasten  the  cooling  ofi", 
so  that  the  oil  may  be  drawn  oft*  into  wooden  vessels. 

If  carefully  conducted  the  palm  oil  thus  bleached  possesses 
either  a  light  yellowish  color,  or  it  is  of  a  greenish  hue 
probably  emanating  from  a  small  quantity  of  copper  from 
the  kettle.  The  soap  boiled  from  it  is  not  entirely  white  when 
fresh,  but  assumes  whiteness  after  being  a  short  time  ex- 
posed to  the  light. 

By  the  bleaching  of  palm  oil,  not  only  the  color  of  the  oil 
and  the  glyceryl  oxide  are  decomposed,  but  the  palmitin 
also  while  losing  1  equivalent  of  carbon  and  1  equivalent  of 
hydrogen  is  changed  into  palmitic  acid  which  causes  a  loss 


104  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


of  about  2.75  per  cent,  in  oil,  which  by  the  bleaching  with 
chromate  of  potassa  and  muriatic  acid  is  avoided. 

Palm  oil  is  sometimes  confounded  with  galam  butter,  shea 
butter,  or  bambuk  butter,  which  has  much  similarity  with  it, 
possesses  a  dirty-white  or  reddish  color,  and  melts  at  80°  0. 
(86°  F.),  readily  becoming  nincid,  and  in  this  acting  similar 
to  palm  oil.  The  galam  butter  is  the  product  of  bassia  par/diy 
a  tree  belonging  to  the  saponaes  species,  growing  in  the  in- 
terior of  Africa.  The  others  are,  we  believe,  derived  from 
the  same  source. 

Palm  Kernel  Oil 

has  recently  made  its  appearance  in  the  market,  and  it  is  but 
a  short  time  since  it  found  application  in  the  manufacture 
of  soap.  It  is  obtained  by  crushing  and  pressing  the  stony 
kernels  which  are  contained  in  the  fruit  of  the  avoira  elais. 
In  the  raw  state  it  has  an  almost  coffee-brown  color  and  a 
peculiar  cocoa-like  fragrance.  Before  its  ap[)lication  to  the 
niaking  of  soap  it  must  be  bleached.  To  do  this,  the  follow- 
ing recipe  will  answer:  50  kilogrammes  (110  lbs.)  of  fat  are 
well  stirred  with  a  rake  in  a  sub-lye  or  in  a  solution  of  culi- 
nary salt  of  26°  B.,  at  a  temperature  of  100°  C.  (212°  F.). 
After  this  it  is  left  to  settle  awhile,  during  which  time  the 
fat  which  has  already  lost  considerable  of  its  color,  rises  to 
the  surface.  It  is  then  scooped  oft',  warmed  to  35°  C.  (95°  F.) 
mixed  with  1  kilogramme  (2.2  lbs.)  of  crude  muriatic  acid 
and  a  solution  of  |  kilogramme  (8.8  ozs.)  chromate  of  potash 
in  water,  and  well  stirred.  On  the  following  day  the  oil  is 
reheated  to  35°  C.  (95°  F.),  and  again  \  kilogramme  bichro- 
mate of  potassa  and  1  kilogramme  muriatic  acid  are  added. 
The  oil  thus  bleached,  called  in  commerce  palmitin  oil,  has  a 
faint  reddish  tint  and  an  agreeable  smell  similar  to  that  of 
a  mixture  of  palm  oil  and  cocoa-nut  oil,  and  in  consequence 
thereof  it  may  be  used  with  good  results  for  making  the  so- 
called  Swiss  soaps,  also  for  colored  toilet  soap,  whicli  in  this 
case  is  not  subject  to  that  disagreeable  odor  which  cocoa-nut 
oil  soda  soap  possesses. 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  105 


CocoA-i^uT  Oil. 

Of  tins  valuable  oil  three  kinds  are  at  present  known  in 
commerce,  Ceylon,  Sidne}',  and  Cochin  China  oils,  the  latter 
beino^  considered  mnch  the  best — whether  from  a  different 
species  of  palm  or  the  care  in  its  preparation  is  not  known. 
These  oils  are  obtained  by  boiling  the  ground  or  crushed 
kernels  of  the  nuts  of  the  cocos  nueifera^  the  cocos  butyracea 
and  perhaps  other  species.  Cocoa-nut  oil  is  a  white  usually 
rancid  fat  of  the  consistency  of  lard  with  an  unpleasant  taste 
and  smell;  it  melts  at  20  to  22°  C.  (68  to  71.6°  F.)  and  con- 
geals at  18°  C.  (b4.40°  F.). 

Tyndall  made  some  experiments,  and  obtained  by  the  opera- 
tion, from  210  kilogrammes  (462  lbs.),  dividing  the  cocoa-nut 
kernels  into  portions  of  3J  kilogrammes  (7.33  lbs.)  in  pressing 
bags  made  of  bast  mats,  various  sorts  of  oil  of  steadily  in- 
creasing melting  points,  after  having  five  times  increased  the 
temp)erature  of  the  masses  which  were  prepared  for  pressing, 
viz., 

1  portion  of  42|  kilogrammes  pressed  at  14-1 50  C.  (57.2-590  F.) 

2  "        6|  "  "         18-190  C.  (fi4.4-66.20  F.) 

3  "       10|  "  "        240C.  (7o.20  F.) 

4  "       13|  "  "         29-300  c.  (84.2-S60  F.) 

5  "       4-|  "         40-410  C.  (104-105.80  F.) 
Together  119^  kilogrammes  (262  lbs.) 

The  remaining  cakes  which  were  pressed  out  weighed  77J 
kilogrammes  (170.5  lbs,),  the  rest  of  13|  kilogrammes  (29.4 
lbs.)  was  mostly  oil  which  runs  down  from  the  press  into  a 
sejjarate  vessel.  From  this  it  is  manifest  that  the  kernels 
contain  60  per  cent,  or  somewhat  more,  and  probably  two 
different  fats,  one  fluid  and  one  solid,  which  in  the  seed  are 
separately  present,  but  during  tiie  process  of  pressing  become 
mixed  with  each  other  the  higher  the  tem]:)erature  becomes. 
So  that,  according  as  may  be  desired,  the  oil  may  be  pressed 
out  at  first  fluid,  then  firm  or  even  of  a  medium  consistency. 
In  fact,  by  the  above  stated  experiment  the  first  and  second 
portions  were  entirely  liquid  and  translucent,  the  third  half 


103 


TECHNICAL  Tl^EATISE  ON  SOAP  AND  CANDLES. 


liquid  and  milky,  the  fourth  firm  and  of  a  dirty-white  color, 
the  fifth  pure  white  and  very  solid. 

The  solid  fat  which  has  received  the  name  kocin  was  for- 
merl}^  deemed  to  be  the  combination  of  a  specific  acid,  viz., 
kocin,  cocoa-nut  tallow,  or  cocoa-nut  stearic  acid,  wnth  oxide 
of  glyceryl.  Heintz,  moreover,  has  shown  that  the  latent 
acid  which  is  contained  in  kocin  combined  with  oxide  of 
glyceryl  is  a  mixture  of  two  difierent  acids,  lauric  and  my- 
ristic,  which  is  in  the  proportion  of  14  parts  of  lauric  with 
3  parts  of  myristic  acid,  with  6  to  6J  parts  of  palmitic  acid, 
and  it  has  the  same  melting  point  as  the  hitherto  presumed 
acid  of  kocin  =  35°  C.  (95°  F.).  Myristic  acid  melts  at  34°  C. 
•  (93.2°  F.),  lauric  acid  at  44°  C.  (111.2°  F.).  The  mixture  has 
therefore  a  lower  melting  point  than  the  average  of  the  two 
acids.  A  similar  action  Heintz  proved  to  exist  in  the  case 
of  palmitic  and  stearic  acids.  In  cocoa  stearine  we  hence  have 
lauric  and  myristic  acids  of  oxide  of  glyceryl. 

The  action  of  cocoa-nut  oil  in  the  process  of  saponification 
is  peculiar,  and  quite  difterent  from  that  of  tallow  and  other 
fats.  The  cocoa-nut  oil  soaj)  can  only  be  separated  by  con- 
centrated solutions  of  culinary  salt,  and  then  becomes  so  ex- 
traordinarily hard  that  it  cannot  be  cut.  For  this  reason 
a  clear  boiling  to  the  solid  would  in  case  of  the  cocoa-nut 
oil  soap  be  entirely  contrary  to  the  end  in  view,  and  very 
difficult.  While  furthermore,  tallow  for  instance  treated 
with  very  strong  lye  floats  above  and  then  can  hardly  or 
not  at  all  be  saponified;  in  the  case  of  cocoa-nut  oil  just  the 
contrar}^  happens.  It  does  not  form  that  milk-like  mixture 
with  weak  lyes  by  which  the  process  of  saponification  is 
usually  preceded,  but  floats  as  a  clear  fat  above,  only  when  by 
a  continued  boiling  and  evaporation  the  lye  has  reached  a 
certain  strength,  the  6a[)onification  suddenly  ensues.  For 
saponifying  cocoa-nut  oil,  In'cs  of  sucli  strength  are  used  that 
the  soap  with  the  lye  receives  the  intended  contents  of  water, 
and  a  separation  thereof  becomes  unnecessary.  Of  course  the 
amount  of  the  alkali  must  be  so  accurately  calculated  that 
the  soap  receives  no  excess  of  alkali,  or  at  least  but  very 
little. 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  107 

The  higlily  disagreeable  odor  which  is  natural  to  cocoa- 
nut  oil  is  retained  by  the  soaps  made  from  it,  and  thus  far 
no  remedy  has  been  made  known  that  is  capable  of  remov- 
ing it.  Since  the  odorous  matter  is  volatile,  it  seems  feasible 
to  remove  it  by  heating.  By  an  experiment  made  for  this 
purpose  this  was  accomplished  only  to  a  certain  degree,  but 
it  is  not  impossible  that  by  a  still  further  continued  and  also 
increased  heating,  this  pur[tose  may  yet  be  accomplished. 
The  gradual  addition  of  a  little  water  to  the  heated  oil  seems 
also  to  operate  efficaciously  in  the  removal  of  the  smell. 

If  cocoa-nut  oil  is  slow^ly  heated  until  it  reaches  165°  C. 
(329°  F.)  it  develops  a  poignant  rancid  smell  not  unlike  that 
of  lacteal  acid;  the  oil  remains  thereby  colorless  and  obtains 
a  high  degree  of  limpidity.  By  continued  heating  to  240° 
C.  (464°  F.)  and  if  this  temi>erature  is  kejtt  constant  for  a 
while,  the  fat  loses  the  capability  of  immediately  congeal- 
ing after  it  cools  oH'.  Only  after  24  hours  a  part  of  such 
oil  becomes  tirm,  which  can  be  easily  pressed  out  from  the 
liquid  mass,  and  it  is  very  solid  and  entirely  colorless.  Per- 
haps this  solid  matter  might  in  many  cases  be  used  to 
advantage  in  the  manufacture  of  candles.  After  remaining 
for  40  hours  exposed  to  the  cold,  the  other  part  of  the  oil 
also  congeals. 

The  properties  of  this  article,  as  given  above,  are  posse?^sed 
in  common  by  the  Cochin  China,  Ceylon,  and  Sidney  cocoa- 
nut  oils;  only  the  latter  are,  as  a  rule,  of  a  somewhat  softer 
consistency,  and  also  less  white  in  color,  than  that  from 
Cochin  China;  nor  does  the  saponification  occur  with  each 
oil  in  the  same  manner,  which  probably  is  caused  by  the 
fact  that  by  the  pressing  of  the  kernels  the  liquid  at»d  the 
solid  fats  are  not  always  kept  mixed  in  the  same  proportions. 

Gallipoli  Oil, 

also  called  Illipe  oil,  or  Bassia  oil,  is  obtained  from  the  seeds 
of  Bassia  latifoUa  and  Bassia  lo-ngifolia.  It  melts  at  26°  to 
28°  C.  (78.8°  to  82.4°  F.) ;  is,  in  its  solid  state,  greenish-white, 
when  melted  yellow,  and  has  a  weak,  not  disagreeable  smell. 


108  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Of  late  it  has  been  much  used  in  Eiio-land  and  France  for 
the  purposes  of  soap  manufacture. 

Almond  Oil. 

This  well-known  oil,  though  making  a  very  superior  soap 
of  a  beautiful  wax-like  iippearance,  is  too  costly  for  any 
except  the  finest  toilet  soaps,  and  then  it  is  generally  mixed 
with  equal  parts  of  refined  hog's  lard.  It  is  found  in  com- 
merce of  a  clear  yellowish-white  color,  and,  if  fresh,  has  no 
odor,  and  is  of  a  pleasant,  sweet,  nutty  taste.  It  is  made  by 
expressing  the  almond  kernels,  which  are  ground  and  steamed 
and  placed  under  heavy  pressure.  The  oil  obtained  is  sub- 
mitted to  the  action  of  steam-heat,  the  impurities  subsiding 
with  the  condensed  water;  tlie  marc  is  dried  and  powdered 
to  make  a  useful  toilet  powder.  Both  the  sweet  and  the 
bitter  almonds  are  used  for  making  the  oil,  the  former  con- 
taining nearly  fifty  per  cent,  of  oil,  while  the  latter  have  less 
than  thirty  per  cent. 

Sesame  Oil. 

This  valuable  oil,  from  the  seeds  of  the  Scsamum  orieiUale^ 
has  many  good  properties  for  forming  a  superior  soap  espe- 
cially adapted  for  the  toilet,  but  generally  in  combination 
with  other  oils  or  fats. 

The  plant,  originally  indigenous  to  India,  however  gene- 
rally thrives  in  warm  climates,  and  is  frequently  cultivated 
as  an  oil  plant.  In  India  three  varieties  are  said  to  be 
known,  viz.,  with  white  seed,  with  partly  colored,  and  with 
brownish-black  seed  grains;  the  latter  furnishing  the  oil  of 
commerce,  and  containing  40  to  50  per  cent.  The  sesame 
seed  comes  in  great  quantities  from  India  and  Africa  to 
Europe,  to  France,  Germany,  and  England,  where  by  press- 
ing the  oil  is  obtained.  It  is  yellowish,  in  a  pure  state 
odorless  and  tasteless.  When  first  pressed  it  tnstes  some- 
what sharp,  but  this  taste  is  soon  entirely  lost.  If  exposed 
to  the  air  for  some  time  it  attains  a  hemp-like  smell.  The 


MATERIALS  USED  IN  THE  xMANUFACTURE  OF  SOAPS.  109 


oil  has  a  specific  gravity  of  0.923  at  15*^  C.  (59°  F.) ;  at  8.° 
C.  (46.4°  F.)  it  coiiireals  and  assumes  a  consistency  like  palm 
oil;  heated  to  150°  to  200°  C.  (302°  to  392°  F.)  it  becomes 
somewhat  lighter  in  color. 

Sesame  oil  finds  a  very  extensive  application  as  table  oil, 
illuminating  oil,  and  especially  for  soap-making.  It  is  used 
in  asimihir  manner  to  olive  oil,  and  serves  frequently  for  adul- 
terating it.  According  to  Pohl  sesame  oil,  mixed  Avith  sul- 
phuric acid,  turns  quickly  to  a  brownish-red  color,  while 
olive  oil  attains  a  green-yellow  or  brownish-yellow  hue;  ac- 
cording to  others  the  presence  of  sesame  oil  in  another  oil 
is  perceivable  by  a  stronger  foaming,  which  becomes  visible 
when  the  oil  is  left  to  descend  in  a  tliin  stream  from  a  height 
of  1.2  to  1.5  metres  (47  to  59  inches).  What  influence  the 
state  of  the  seed,  the  age  of  the  seed,  and  the  manner  of 
pressing  have  on  the  projierties  of  the  oil,  has  not  yet  been 
ascertained.  Soda  soap  made  from  sesame  oil  always  re- 
mains somewhat  soft,  and  hence  it  is  best  applied  for  mak- 
ing soft  soap,  or  added  to  fats  making  a  hard  soap. 

Rapkseed  Oil  and  Coleseed  Oil. 

This  last  named  oil  is  acquired  from  Brassica  campesMs. 
The  seeds  give  40  per  cent  of  their  weight  of  a  light,  thin- 
nish,  limpid  oil,  whose  si)ecific  gravity  is  0.913.  Br.issici 
nifus  furnishes  the  so-called  rapeseed  oil,  which  has  a  pecu- 
liar smell.  In  all  other  respects  these  oils  show  congruous 
action,  and  are  adapted  for  making  soft  soap.  The  soda 
soaps  remain  always  somewhat  soft. 

Groundnut  Oil. 

This  oil  is  obtained  from  the  fruit  of  the  Arachis  hypogma^ 
a  legumine  plant.  Tiiis  small,  creeping  plant  is  indigenous  to 
South  America  and  the  coasts  of  southern  Africa  and  Asia. 
Since  the  later  part  of  the  last  century  it  has  been  cultivated 
in  our  Southern  States,  and  in  Italy,  Spain,  and  the  southern 
parts  of  France. 


110  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

The  plant  is  small  and  has,  like  many  plants  of  the  same 
species,  an  inclination  to  twine  around  other  objects.  As 
soon  as  the  fruit  commences  to  form,  the  blossom-bearing 
stem  has  a  particular  inclination  to  creep  into  the  soil. 
Blossoms  which  do  not  reach  under  the  soil,  remain  either 
not  bearing  or  the  fruit  does  not  ripen.  In  the  cultivation 
of  the  [)lant,  the  main  thing  consists  in  taking  care  that  all 
stems  which  haveiinished  blossoming  are  covered  with  earth. 
In  the  wild  state,  the  plant  produces  five  or  six  pods  or 
shells;  but  their  number  increases  greatly  in  the  cultivated 
state.  The  pods  are  2J  to  3J  centimetres  (0.97  to  1.36  inches) 
long,  have  one  to  three  seeds  in  each,  and  have  dirty-yellow- 
ish, leather}',  rugged,  lengthwise-raised  shells.  The  fruit 
itself  is  longitudinally  round,  outside  covered  by  a  very  thin, 
curly,  brown  skin;  it  is  white  similar  to  white  beans,  which 
it  in  taste  also  resembles,  if  the  oily  taste  be  not  considered. 
When  roasted  it  does  not  taste  unlike  tlie  roasted  almond, 
for  which  it  is  often  a  substitute.  In  Spain,  its  flour  is 
mixed  with  the  roasted  fruit  of  cocoa,  or  it  is  used  as  a  sub- 
stitute for  the  latter.  Its  oil  has  a  light  green  color,  and 
does  not  seem  to  become  easily  rancid.  It  furnishes  an  ex- 
cellent soap,  which  is  firm,  white,  and  odorless.  Within  the 
last  few  years,  it  has  for  this  purpose  been  applied  in  Ger- 
many, France,  and  elsewhere  with  profit. 

Ben  Oil 

is  obtained  from  the  seeds  of  tlie  Galaridira  moriiiga  and  is 
very  applicable  in  perfumery,  it  having  the  property  of  re- 
sisting rancidity  better  than  almost  all  known  oils.  For 
this  reason  it  is  used  in  oiling  clocks.  The  more  solid  parts 
are  extracted  by  congealing  the  oil  and  thelim[)i<l  oil  used  for 
this  purpose.  For  soaps  this  oil  has  no  advantages  over 
sesame  and  some  other  oils,  while  it  is  usually  much  higher 
in  price. 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  Ill 


Avocado  Oil 

is  an  oil  obtained  from  the  oleaginous  fruit  of  the  avocada 
pear  tree  {Laurus  fcrsia)^  a  native  of  Trinidad.  It  is  very 
similar  to  palm  oil  in  its  action  with  the  alkaline  bases,  but 
has  less  coloring  matter,  and  forms  a  good  soap  without  being 
bleached,  but  can  be  easily  bleached  to  make  a  white  soap. 

Sunflower  Oil. 

The  oil  from  the  seeds  of  the  Helianthus  annum  is  a  re- 
markably fine  oil  for  the  fabrication  of  soaps.  It  is  a  light- 
colored,  sweet-tasted  oil,  and  we  think  deserves  especial  at- 
tention, for  it  it  were  cultivated  it  might  form  a  profitable 
material  for  many  other  purposes  besides  soaps.  The  soaps 
made  from  it  with  soda  lye  have  a  fine  appearance,  remaining 
plastic,  and  have  the  quality  of  retaining  much  w^ater. 

Cotton-seed  Oil, 

now^  much  used  in  soaps  and  to  adulterate  more  costly  oils, 
has  many  properties  that  recommend  it  to  the  soap-maker, 
besides  its  usual  low  price,  and  we  give  it  a  somewljat  ex- 
tended notice.  It  is  extracted  from  the  seed  of  the  cotton 
plants,  Gossipium  herbareum^  G.  arboreum,  and  other  varieties. 
When  deprived  of  their  fibres  the  seeds  are  bruised,  and 
heated  up  to  from  75°  to  88=  0.  (167=  to  190.4=  F.),  and  by 
pressure  eighteen  to  twenty  per  cent,  of  oil  is  obtained, 
which  has  a  dark-brown  color.  This  oil  has  in  its  crude 
state  at  12.2=  C.  (54=  F.)  a  specific  gravity  of  0.931,  after 
being  washed  in  a  jet  of  steam  of  1U0=  C.  (212=  F  ),  0.934 
at  10=  C.  (5u°  F.).  The  raw  cotton-seed  oil  smells  and 
tastes,  and  is  otherwise,  except  in  color,  similar  to  linseed 
oil,  and  it  can  be  substituted  for  it  for  many  purposes.  The 
raw  oil  congeals  at  —2=  to  —  3=  C.  (28.4°  to  26.6=  F.),  and 
is  most  excellently  suited  for  furnishing  hard  and  soft  soa[)S. 
The  so-called  refined  cotton-seed  oil,  the  best  quality  of  which 
is  fully  equal  to  the  lower  qualities  of  olive  oil  as  to  smell  and 


112  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


taste,  congeals  between  2°  and  0^  C.  (35.6°  and  32°  F.),  and 
its  specific  gravity  at  16°  C.  (60.8°  F.)  is  0.926  to  0.927. 

In  large  quantities  the  oil  appears  reddish,  while  in  smaller 
quantities  it  is  more  or  less  of  a  dark  dirty-yellow.  If  a  few 
drops  of  cotton-seed  oil  are  placed  in  a  test  glass  and  mixed 
with  a  solution  of  chloride  of  zinc,  it  will  become  dark  brown, 
while  rapeseed  oil  becomes  golden  yellow,  and  olive  oil  green  ; 
pure  sulphuric  acid  turns  it  instantly  dark  red-brown.  Rape- 
seed  oil  treated  in  the  same  manner  becomes  green,  and  olive 
oil  assume  a  light  orange-yellow.  Perchloride  of  tin  turns 
cotton-seed  oil  into  a  thick  translucent  mass  of  orange-red 
color,  while  rapeseed  oil  thus  treated  will  become  green,  and 
olive  oil  greenish-blue,  but  neither  of  these  two  will  thicken. 
Phosphoric  acid  colors  cotton-seed  oil  under  ebullition  to  a 
golden  yellow;  rapeseed  oil  treated  in  the  same  way  turns 
whitish-blue,  olive  oil  bluish-green.  By  means  of  these  re- 
actions, it  is  easy  to  ascertain  whether  cotton-seed  oil  has 
been  used  in  adulterating  rai.>e-seed  oil  or  olive  oil. 

The  better  grades  of  cotton-seed  oil  are  frequently  mixed 
with  exi)ensive  oils,  and  there  are  many  firms  in  England 
and  the  United  States  who  refine  cotton-seed  oil,  of  which 
enormous  quantities  are  sent  to  Italy,  to  serve  in  the  adul- 
teration of  olive  oil.  The  loss  caused  by  the  process  of  re- 
fining is  between  twelve  and  fifteen  per  cent. 

The  modus  operandi  of  this  refining  is  at  present  not  gene- 
rally known.  Although  Pohl  had  the  following  process  for 
refining  patented,  yet  it  seems  to  us,  that  it  cannot  be 
rational.  According  to  this  process  the  seeds  are  crushed 
between  iron  rollers,  and  pressed  in  iron  presses,  whereby 
a  dark  crude  oil  and  an  excellent  oil  cake  are  obtained, 
which  latter  is  very  useful  for  feeding  cattle.  100  parts  of 
the  crude  oil  are  mixed  with  12  parts  of  a  mixture  which 
consists  of  a  solution  of  potash  of  42°  B.,  a  solution  of  tartaric 
salts  of  42°  B.,  and  milk  of  lime  of  10°  B.  This  solution  is  to 
be  mixed  with  the  heated,  almost  boiling  oil,  the  entire  mass 
stirred  for  a  period  of  two  hours,  and  then  allowed  to  rest  for 
twenty-four  liours,  when  the  oil  will  have  lost  its  dark  color 
and  may  be  filtered.    After  filtration,  and  after  the  oil  has 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  113 


been  nearly  drawn  ott",  there  still  remains  a  residue  with  some 
oil,  which  is  boiled  for  two  hours  with  ten  per  cent,  of  strong 
salt  water.  The  oil  rises  to  the  surface,  and  can,  when  the 
residue  has  become  firm,  after  a  little  while  be  poured  out, 
and  tlien  applied  in  the  usual  way  to  make  a  good  soap.  (See 
formulas  for  these  soaps.) 

Castor  Oil. 

This  oil  is  extracted  from  the  seed  of  the  shrub  Rlcinus 
conununis,  either  by  pressing  in  the  cohl  way,  or,  as  is  fre- 
quently done  in  this  country,  by  a  slight  roasting  and  crushing 
of  the  seeds  and  boiling  in  water,  whereby  the  oil  gathers  on 
the  surface,  when  it  is  skimmed  off,  and  by  heating  is  freed 
from  water  and  afterwards  filtered.  If  the  seeds  are  at  first 
pressed  while  cold,  and  afterwards  moistened  with  alcohol, 
and  pressed  out  a  second  time,  about  30  per  cent,  more  oil  is 
obtained.  This  is  a  pale  yellow,  nearly  odorless,  and  a  very 
thick  liquid  ;  its  specific  gravity  is  0.951.  In  the  cold  it  con- 
geals slowly.  While  fresh  it  is  odorless  and  of  mild  taste  ; 
exposed  to  the  air  it  soon  becomes  rancid  ;  by  shaking  it  with 
water  and  calcined  magnesia  this  rancidity  can  be  removed. 
In  small  portions  it  slowly  dries  when  left  exposed  to  the 
air.  In  the  saponification  ricinus  oil  furnishes  three  acids: 
1st,  the  stearic  ricinic  acid,  which  melts  at  74°  G.  (165.2°  F.); 
2d,  ricinic  acid,  at  22°  C.  (71.6°  F.);  and  3d,  the  acid  of  oil  of 
ricinus,  which  melts  somewhat  below  0°  C.  (32  ^  F.).  Ricinus 
oil  has  the  property,  when  saponified  with  soda,  of  furnish- 
ing transparent  soaps;  but  for  this  purpose  the  lye  has  to  be 
entirely  free  from  other  salts  or  carbonic  acid.  It  is  particu- 
larly suitable  for  toilet  soaps. 

Poppy-seed  Oil. 

Extracted  by  expression  from  the  seeds  of  the  Papaver  som- 
niferum.    When  pure  it  resembles  olive  oil  in  its  appearance 
and  taste.    It  is  nearly  colorless,  or  of  a  yellow  color.  Its 
specific  gravity  is  0.9249  at  15°  C.  (59°  F.).    It  solidifies 
8 


114  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


at  — 17.7°  0.  (0°  F.).  The  concrete  oil  sometimes  retains  this 
state  at  —2.2°  C.  (i8°  F.).  It  becomes  rancid  with  difficulty; 
It  is  soluble  in  25  parts  of  cold,  and  6  of  boiling  alcohol ;  it 
mixes  in  all  proportions  with  ether.  It  is  very  siccative.  It 
has  nothing  of  the  narcotic  properties  of  the  poppy. 

To  effect  its  extraction,  break  the  capsules  as  soon  as  they 
have  experienced  a  certain  degree  of  desiccation.  Separate 
the  seeds,  and  sift  them  so  as  to  get  rid  of  the  dirt;  reduce 
them  to  a  kind  of  flour,  which  is  put  into  coarse  cloth  bags, 
and  submitted  to  the  action  of  the  press.  The  oil  is  col- 
lected in  earthen  jars  and  allowed  to  rest ;  then  decanted  and 
put  into  barrels. 

Before  the  introduction  of  sesame  and  earthnut  oils  into 
the  fabrication  of  Marseilles  soap,  this  oil  was  used  in  a  cer- 
tain proportion  for  the  fabrication  of  marbled  soap.  The 
reason  for  such  an  addition  was  that  olive  oil  alone  gave  too 
hard  a  soaj* ;  an  addition  of  from  10  to  £0  per  cent,  of  black 
poppy  oil  attenuated  the  strong  consistency  of  the  soap  and 
rendered  it  more  unctuous  and  soft,  and  it  retained  its  water 
much  lono;er. 

Hempseed  Oil. 

Extracted  from  the  seeds  of  the  cultivated  hemp,  Cannabis 
sativa.  The  composition  of  hempseed  varies  a  little  according 
to  the  specimen,  as  may  be  seen  by  the  following  analyses: — 

Oil   33.6  35.65 

Organic  matter  .       .       .       .       .  23.6 

Nitrogenized  malter   ....  16.3  V  51.31 

Lignin   12,1  * 

Mineral  substances     ....  2.2  7.39 

Water   12.2  5.65 

100.0  100.00 

When  fresh,  hempseed  oil  is  of  a  greenish-yellow  color;  it 
becomes  yellow  with  time;  its  odor  is  disagreeable,  and  its 
taste  sickly;  its  density  equals  0.9252  at  15.5°  C.  (60°  F.). 
It  thickens  at  — 15°C.(5°F.)  and  concretes  at  — 27.5° C.  (17.5° 
below  0°  F.).  It  is  soluble  in  all  proportions  in  boiling  alco- 
hol, but  requires  SO  per  cent,  of  cold  alcohol  to  dissolve  it. 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  115 


The  process  for  obtaining  it  consists,  the  same  as  with  all 
the  other  oils,  in  reducing  the  seeds  to  flour,  submitting  the 
latter  to  the  action  of  the  press,  and  purifying  the  oil  ob- 
tained with  sulphuric  acid,  or  with  caustic  alkali.  It  is 
used  in  the  fabrication  of  soft  soaps,  of  green  soaps,  especially 
when  this  fabrication  is  carried  on  in  winter,  because  it  can 
be  submitted  to  a  very  intense  cold  without  solidifying.  It 
is  also  added  to  castile  soaps  to  keep  them  softer. 

Nut  Oil. 

Extracted  from  the  walnut,  fruit  of  the  royal  nut  tree 
Juglnns  regia.  The  oil  recently  extracted  is  fluid,  nearly 
colorless,  with  a  faint  odor,  and  a  taste  which  is  not  disagree- 
able. The  oil  of  the  second  pressure  is  greenish,  caustic,  and 
siccative.  The  oil  extracted  from  the  unpeeled  kernel  has 
generally  a  greenish-yellow  color. 

Its  specific  gravity  at      .       .    120  C.    (53.60  F.)  =  0.9283 
.       .    250  C.      (770  F.)  =  0.9194 
"         '     .       .    940  C.  (201.20  F.)  =  0.8710 

At  —15°  C.  (5°  F.)  it  thickens,  and  at  —26.1°  C.  (15° 
below  0^  F.)  it  takes  the  consistency  of  a  white  mass. 

The  extraction  of  the  oil  must  be  made  only  two  or  three 
months  after  the  fruit  has  been  gathered.  After  separat- 
ing the  kernels  and  peeling  them,  they  are  crushed,  so  as  to 
form  a  paste,  which  is  put  into  bags  and  submitted  to  the 
action  of  the  press.  The  oil  which  runs  first  is  called  virgiii 
oil,  and  is  used  as  an  aliment ;  the  residium  is  moistened  with 
boiling  water,  and  is  pressed  anew  ;  this  second  oil  is  reserved 
for  manufacturing  purposes.  ITuts  give  about  50  to  60  per 
cent,  of  oil.  This  oil  enters  into  the  composition  of  green 
soaps  ;  it  is  employed  also  for  lighting. 

Beech-nut  Oil. 

Extracted  from  the  fruit  of  the  beech  {Fagus  sylvatica). 
This  oil  is  of  a  light-yellow  color,  with  a  peculiar  odor,  a 
sickly  taste,  thick  and  muddy  when  first  extracted ;  it  is 


116  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


limpid,  although  a  little  viscous,  after  a  sufficient  rest.  Its 
specific  gravity  is  0.9225  at  15.5°  C.  (60°  F.) ;  at  —17°  C. 
(1.4°  F.)  it  congeals  into  a  yellowish-white  mass.  It  may 
be  kept  a  long  time  without  alteration,  and,  unlike  other 
oils,  it  improves  by  age.  It  forms  with  soda  a  soap  firm 
enough,  but  which  remains  plastic. 

The  kernels  are  reduced  to  a  pulp,  which  is  put  into  coarse 
cotton  bags,  and  submitted  to  the  action  of  the  press ;  the 
resulting  oil  is  stored  in  large  jars,  to  allow  it  to  deposit  the 
mucous  parts,  and  the  oil  thus  refined  is  ready  for  the  market. 
This  process  generally  gives  from  15  to  20  per  cent,  of  oil. 

Cameline  Oil. 

A  drying  oil  of  a  light-yellow  color  extrncted  from  the 
seeds  of  the  Myagrum  sativum.  It  has  a  peculiar  taste  and 
odor,  and  is  much  employed  on  the  continent  of  Europe  in 
combinations  for  fabricating  soft  soaps,  for  which  it  is  well 
adapted,  as  it  tends  to  make  them  clearer.  Its  specific  gravity 
is  0.926;  it  congeals  at  0°  C.  (32°  F.). 

Mustard-seed  Oil. 

This  oil,  abundantly  produced  in  making  table  mustard, 
is  extracted  from  the  seeds  of  the  Slnapis  nigra  and  Sinapis 
alba^  is  a  valuable  oil  for  many  purposes  besides  soaps.  The 
-white  mustard  yields  about  36  per  cent,  of  oil,  the  black 
about  halt'  that  quantity.  The  soap  from  this  oil  is  of  a 
superior  quality. 

Colza  Oil, 

obtained  from  the  seed  of  the  Bmssica  campestris  to  the 
amount  of  nearly  40  per  cent,  of  its  weight,  is  a  very  fine 
oil  much  used  on 'the  continent  of  Europe  as  a  lamp  oil.  It 
makes  an  excellent  soap  with  soda  lye. 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  117 


Hazel-nut  Oil, 

made  from  the  nuts  of  the  corylus  avellana,  which  are  very 
rich  in  oil,  yielding  nearly  60  per  cent.,  is  a  very  fine  oil  of  a 
pale-j'Cllow  color,  analosjous  to  almond  oil,  for  which  it  is 
often  substituted  in  perfumery  and  pharmacy.  It  also  makes 
a  beautiful  soap,  though  too  costly  for  general  use. 

Linseed  Oil 

is  obtained,  as  is  well  known,  from  the  seeds  of  the  flax 
l>lant,  TAnum.  usitatissimum^  by  pressure  and  the  aid  of  heat. 
These  seeds  furnish  in  their  dry  state  from  25  to  30  per 
cent,  of  oil,  which  possesses  a  beautiful  yellow  color  and 
a  peculiar  smell.  It  is  rather  limpid,  and  even  at  a  very 
low  temperature  does  not  congeal.  Beside  the  liquid  gly- 
ceryl-oxide  combination,  it  contains  a  small  portion  of  pal- 
niitin.  Exposed  to  the  air,  the  oil  dries  to  a  tough  mass, 
which  when  entirely  dry  is  insoluble  in  ether  or  alcohol.  The 
olein  of  linseed  oil  is  the  combination  of  oxide  of  glyceryl 
with  a  peculiar  acid,  which  in  many  of  its  properties  varies 
from  the  oleic  acid  of  other  fat  substances.  This  oil  when 
exposed  to  the  air  very  easily  changes,  and  absorbs  oxygen 
rapidly.^  Oxidized  oleic  acid,  if  treated  with  alkalies,  fur- 
nishes dark  colored  soap.  Fresh  linseed  oil  saponified  with 
soda  makes  a  soft  soap  of  a  light-^^ellow  color,  of  which,  by 
adding  culinary  salt,  solid  soda  soap  may  be  obtained.  If  this 
is  exposed  in  thin  layers  to  the  open  air,  it  will  become  dry 
and  yellow.  After  a  few  weeks  it  may  be  dissolved  in  water 
mixed  with  soda  and  salt.  If  this  process  be  repeated,  the 
liquid  receives  an  almost  black  hue,  a  yellow  soap  will  be 
the  result,  which  in  a  great  measure  contains  only  palmitic 
acid,  while  the  oleic  acid  has  been  destroyed ;  by  decomposing 
with  muriatic  acid,  a  brown  substance  separates. 

Oleic  Acid,  Olein,  Commercial  Red  Oil. 

The  oleic  acid  which  is  found  in  commerce  is  obtained  as 
an  auxiliary  product  in  the  fabrication  of  stearic  and  palmitic 


118 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


acids  for  making  stearin  acid  candles.  As  by  this  process  the 
solid  acids  are  never  completely  separated  from  the  oleic  acid, 
it  contains  more  or  less  stearic  acid  or  palmitic  acid. 

Pure  oleic  acid  is  a  liquid  as  clear  as  water,  scentless,  and 
tasteless,  of  an  oily  consistency,  and  does  not  redden  litmus 
paper,  either  by  itself  or  in  alcoholic  solution.  It  is  not 
soluble  in  water,  but  with  alcohol  and  ether  is  easily  mixed. 
At  4°  C.  (3fc).2°  F.)  it  congeals  into  a  white  crystalline  mass. 
B}^  dry  distillation  it  passes  over  but  little  altered  into  the 
receiver,  and  it  may  be  distilled  by  the  steam  bath  without 
any  decomposition.  By  mixing  with  hydrate  of  potassa, 
oleic  acid  is  divided  into  palmitic  and  acetic  acids;  at  the 
common  temperature  it  absorbs  a  large  amount  of  oxygen, 
but  a  much  more  rapid  absorption  takes  place  at  100'^  C. 
(212°  F.),  when  the  oleic  acid  assumes  a  yellow  or  brownish 
color,  becomes  rancid  with  acid  reaction,  and  loses  the  power 
to  congeal  at  a  lower  temperature.  E'itric  acid  changes  the 
oleic  acid  in  a  short  time  into  elaidic  acid. 

The  common  oleic  acid  of  commerce,  which  has  suffered 
more  or  less  from  the  changes  caused  by  the  influence  of  the 
air,  is  brownish-yellow  or  brown,  rancid  with  acid  reaction. 
It  makes  a  difference,  whether  the  oleic  acid  was  obtained 
by  saponification  of  the  fat  with  lime  and  separation  with 
sulphuric  acid,  or  by  the  process  of  the  so-called  acfdy  sapo- 
nification and  distillation.  The  latter  is  generally  rejected 
by  soap  manufacturers  for  the  production  of  soda  soaps,  and 
is,  therefore,  much  cheaper  than  that  obtained  by  the  pro- 
cess of  saponification  with  lime  in  the  fabrication  of  stearic 
acid.  According  to  Stas,  the  natron  soap,  produced  from 
distilled  oleic  acid,  does  not  retain  as  much  water  as  soap 
made  with  the  oleic  acid  made  by  the  saponification  of  lime. 
According  to  Buff,  the  former  possesses  a  sharp  disagreeable 
smell,  and  its  potash  soap  has  not  the  property  of  becom- 
ing soluble  in  potash  lye.  This  is  the  case,  only  when  oleic 
acid  has  been  distilled  at  too  high  a  temperature.  It  is 
to  be  questioned,  whether  a  stream  of  steam  and  a  tempe- 
rature of  250°  C.  (482°  F.)  are  suflicient  to  volatilize  the 
sebacic  acids,  which  have  already  been  separated  by  sulphuric 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  119 


acid,  viz. :  whether  stearic  and  palmitic  acids  do  not  require 
a  higher  degree  of  temperature,  for  their  separation  from  the 
oleic  acid  and  their  volatilization,  and  furthermore,  whether 
the  oleic  acid,  separated  by  sulphuric  acid  from  glycerine,  has 
not  been  already  so  changed  that  it  will  act  differently  from 
that  which  has  been  obtained  by  the  saponification  of  lime. 

The  soap  manufacturer  has,  therefore,  always  cause  to  ob- 
serve the  difference  in  the  two  kinds  of  oleic  acid,  which 
are  in  commerce,  and  to  direct  his  attention  to  a  possible 
adulteration  of  the  oleic  acid  with  the  cheaper  kind.  The 
small  quantities  of  sulphate,  which  will  be  formed,  cannot 
be  injurious  to  the* soap,  since  the  api>lied  alkalies,  as  potash 
or  soda,  already  contain  large  quantities  of  sulphate. 

In  the  fabrication  of  soap  oleic  acid  serves  principally  in 
producing  soft  or  potash  soaps,  especially  the  so-called  elain 
soaps,  for  which  equal  equivalents  of  potash  and  soda  with 
the  necessary  amount  of  oleic  acid  are  boiled.  But  there  is 
also  a  solid  olein  soap  made,  as  will  be  described  hereafter. 
Accurately  speaking,  caustic  alkalies  would  not  be  required 
in  order  to  change  oleic  acid  into  soap,  since  it  combines 
easily  with  the  carbonated  alkalies.  But  in  fact  there  would 
be  very  little  gained  by  it,  for  by  the  mixing  of  oleic  acid 
with  the  solutions  of  carbonic  acid  alkalies  there  ensues 
such  a  strong  ebullition  of  the  mass,  owing  to  the  escape  of 
the  carbonic  acid,  that  the  lye  can  only  be  added  in  small 
portions.  This  is  troublesome,  and  takes  much  more  time 
than  if  the  alkalies  are  ap[)lied  in  the  caustic  state.  Besides 
this,  soaps  which  are  made  with  carbonate  of  soda  always  re- 
tain a  spongy  quality,  which  is  not  desirable  to  consumers. 

We  have  seen  above,  that  oleic  acid,  when  melted  with 
hydrate  of  potash  and  moreover  with  an  overplus  of  it,  will 
be  dissolved  into  palmitic  and  acetic  acids.  According  to 
theory  there  are  thereby  originated,  from  100  parts  of  oleic 
acid,  about  90  or  91  parts  palmitic  acid.  Since  the  latter  has 
almost  the  threefold  value  of  oleic  acid,  while  this  by  its 
change  into  palmitic  acid  loses  only  10  per  cent,  of  its  weight, 
it  would  be  of  great  advantage,  if  it  could  be  changed  in  a 
cheap  and  easy  manner  into  palmitic  acid.   Such  an  operation 


120  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


is  proposed  by  Juenneman,  who  describes  it  in  the  following 
way  :  In  the  cover  of  a  modern  vat,  several  vessels  of  stone 
are  so  applied,  that  not  only  the  cover  upon  the  vat,  but  also 
the  vessels  of  stoneware  fit  tightl}^ ;  on  the  bottom  a  ser- 
pentine pipe  is  fixed  which  conveys  the  steam.  The  oleic 
acid  is  now  poured  into  the  stoneware  vessels  and  10  per  cent, 
of  common  nitric  acid  is  added,  then  steam  is  admitted 
through  the  pipe  into  the  vat  (it  is  best  to  apply  surcharged 
steam)  and  the  mixture  is  thereby  heated  to  100^  C.  (212*^ 
F.),then  one  per  cent,  finely  powdered  starch  flour  is  gradu- 
ally added  ;  an  operation  by  which  in  the  first  place  the  forma- 
tion of  palmitic  acid  is  intended,  which,  as  we  have  already 
stated  above,  changes  the  oleic  acid  into  the  solid  elaidic 
acid,  being  isomeric  to  it.  A  strong  ebullition  insues,  the 
mass  being  stirred  for  about  one  hour,  is  kept  at  an  equal 
temperature,  then  ladled  over  into  another  vat,  and  with 
sufiicient  w^ater  by  means  of  steam,  boiled  out.  Thus  the 
oleic  acid  has  become  a  light  yellow  mass,  which  melts  at 
45^  C.  (118°  F.),  i.  e.,  elaidic  acid.  It  is  then  placed  in  a 
copper  kettle,  with  an  equal  weight  of  hydrate  of  lime 
added  thereto.  This  kettle  of  copper  is  inserted  in  an  iron 
kettle,  from  the  sides  of  which  it  must  have  a  space  of  5 
centimetres  (1.95  inches),  the  space  between  is  to  be  filled  with 
melted  paraffine  ;  into  one  of  the  kettles  a  thermometer  is  in- 
serted, which  for  the  security  of  its  scale,  is  surrounded  by  a 
pipe  made  of  copper.  The  hydrate  of  lime  is  made  by  sprink- 
ling caustic  lime  with  boiling  lye  of  potash,  whereby  the  lime 
is  reduced  to  a  fine  powder,  which  must  be  used  at  once. 
Now,  the  outer  kettle  is  to  be  heated,  until  the  elaidic  acid 
contained  in  the  inner  kettle  has  reached  a  temperature  of 
220°  to  230^  C.  (428^  to  446^  F.),  wiiich  heat  is  to  be  re- 
tained, while  constantly  stirring  with  an  iron  ladle,  for  seven 
or  eight  hours.  Then  a  sample  is  taken  out,  in  order  to  as- 
certain, by  analysis  with  diluted  sulphuric  acid,  whether  all 
the  fat  has  been  changed  into  palmitic  acid.  As  soon  as 
this  is  the  case,  the  fat  is  transferred  into  a  suitable  appara, 
tus  for  distilling,  and  distilled  after  adding  the  requisite 
quantity  of  sulphuric  acid  and  a  stream  of  surcharged  steam. 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  121 


That  which  passes  over  is  pure  palmitic  acid,  a  firm,  white 
mass,  which  melts  at  62°  C.  (143.6°  F.),  and  can  be  applied  to 
manufacture  the  so-called  stearic  acid  candles  of  priinequality. 
Tliis  product,  however,  has  not  yet  found  practical  appli- 
cation. 

Although  soap  manufacturers  do  not  require  the  pure  pal- 
mitic acid,  they  can  make  use  of  it,  to  mix  it  with  a  suitable 
proportion  of  oleic  acid  (3  parts  oleic  ncid,  2  parts  of  palmitic 
acid),  thus  reestablishing  the  original  projjortion  of  the  liquid 
to  the  solid  acid,  and  for  obtaining  a  mixture  of  sebacic  acids, 
from  whicli  fine  and  solid  soaps  may  be  produced. 

Vegetable  Tallow. 

By  this  name  a  fat,  which  is  pressed  out  of  the  seeds  of 
Brindonia  indica^  is  known.  The  seeds  give  75  per  cent,  of 
their  weight  in  fat  of  a  grayish-wdiite  color,  and  of  the  consist- 
ency of  common  tallow,  with  which  it  has  much  similarity. 
This  product  can  be  purified  and  bleached  by  treating  it  with 
about  one-half  per  cent,  of  concentrated  sulphuric  acid,  pre- 
viously diluted  with  water.  After  sufficient  influence  of  the 
acid  is  had,  it  is  removed  by  washing  it  out.  With  soda 
vegetable  tallow^  makes  a  hard,  wiiite,  and  odorless  soap.  It 
is  thought  that  this  article  might  be  profitably  used  for  manu- 
facturing soap. 

Shea  Butter  or  Galam  Butter. 

A  vegetable  fat  which  has  only  recently  been  introduced 
into  commerce.  It  is  of  the  consistency  of  butter,  and  of  a 
gray  or  greenish-white  color,  and  is  obtained  from  the  dried 
and  bruised  seeds  of  Bassia  parkii^  by  boiling  them  in  w^ater, 
and  by  skimming  oft'  the  rising  fat.  Its  melting  point  varies 
from  23°,  24°,  29°  to  35°  C.  (73.4°,  75.2°,  84.2°  to  95°  F.). 
Shea-butter  furnishes  a  very  hard  and  w^hite  soap,  which 
lathers  but  little,  but  for  its  first  mentioned  peculiarity  miglit 
be  used  with  good  results,  to  make  solid  soaps  from  weaker 
sorts  of  fat. 


122  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Butter  of  Nutmeg  or  Oil  of  Mace. 

•  Extracted  from  the  kernel  of  the  nutmeg,  fruit  of  the 
nutmeg  tree,  Myristica  aromatica,  M.  offi<-inalis.,  M.  rnoschata. 

Pure  butter  of  nutmegs  has  a  pale  yellow  color;  its  odor 
and  taste  are  strong  and  sweet  ;  it  is  composed  of — 


Concrete  oil,  similar  to  tallow      .       .       .  .43.07 

Yellow  biUyrous  oil  58.08 

Volatile  oil  4.85 


106.00 


By  pressure,  in  filtering  paper,  and  by  repeated  solutions, 
and  crystallizations  in  ether,  a  solid  matter  is  extracted  from 
the  butter  of  nutmeg,  called  myristin.  Submitted  to  distil- 
lation it  yields  about  one-eighth  of  its  weight  of  volatile  oil. 

The  nutmeg  contains  two  oils,  one  volatile,  and  the  other 
fixed  and  concrete  ;  the  first  is  a  whitish-yellow,  lighter  than 
water,  with  an  acrid  and  pungent  taste,  and  an  odor  of  nut- 
megs; the  second  is  white  without  taste  and  odor.    It  gives 


by  analysis : — 

• 

White  insoluble  substance  (stearin)  .  .  ,  24.00 
Butyrous  insoluble  colored  substance     .       .  .7.60 

Volatile  oil  6.00 

Acid  (by  approximation)  0.80 

Fecula  2.40 

Gum  1.20 

Ligneous  residuum  54.00 

Loss  4.00 


100.00 

The  mace  or  outside  envelop  of  the  nutmeg  contains  also 
two  difi^erent  oils,  one  fixed  and  the  other  volatile.  This 
butter  is  principally  prepared  in  Holland  in  the  following 
manner:  Fresh  nutmegs  are  crushed  in  a  mortar  and  are 
slightly  heated  until  reduced  to  a  paste ;  they  are  then  intro- 
duced into  cotton  bags,  and  pressed  between  metallic  plates 
previously  heated. 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  123 


Tallow  of  Yirola. 

Extracted  from  the  fruit  of  the  Myristica  sebifera. 

This  kind  of  vegetable  tallow  is  found  in  commerce  in  the 
form  of  square  masses,  similar  to  cakes  of  soap,  but  not  so 
long  nor  so  thick.  They  are  often  covered  with  a  kind  of 
efflorescence  of  a  nacreous  appearance,  which  exudes  in  the 
same  manner  as  benzoic  acid.  This  tallow  melts  at  43°  C. 
(109.4°  F.),  and  is  soluble  in  alcohol  and  ether.  The  mode  of 
extraction  consists  in  crushing  the  kernels  and  boiling  the 
paste  in  water ;  the  fatty  substance  separates  and  collects  on 
the  surface,  where  it  solidities  on  cooling. 

Oil  of  Laurel. 

Extracted  by  expression  from  the  berries  of  the  laurel  of 
Apollo,  Laurus  nobilis. 

The  oil  of  laurel  found  in  commerce  is  green,  with  a  buty- 
rous  consistency,  and  slightly  granular,  similar  in  appearance 
to  half-solidified  olive  oil.  It  contains  a  volatile  oil  which 
gives  it  a  disagreeable  odor.  It  melts  by  the  heat  of  the 
hand  at  about  40°  C  (104°  F.).  Alcohol  extracts  from  it  the 
green  coloring  substance  and  the  volatile  oils;  it  leaves  a 
colorless,  concrete  oil,  similar  to  tallow.  This  solid  part  has 
received  the  name  of  Laurine.  The  fruit  of  the  laurel  con- 
tains two  kinds  of  oils — one  volatile,  which  resides  in  the 
pericarp;  the  other  fixed,  which  is  furnished  by  the  kernel. 
The  first  is  obtained  by  distillation,  and  the  other  by  decoction. 
To  obtain  the  concrete  oil,  the  fruit  is  crushed  and  reduced 
to  a  paste  which  is  boiled  with  water  ;  the  mixture  is  strained 
and  pressed ;  the  grease  formed  of  a  fixed  and  a  volatile  oil 
solidifies  on  the  surface,  and  is  removed  and  melted  anew 
over  a  water  bath  to  expel  the  water.  It  is  kept  in  closed 
vessels. 

Cocoa  Butter. 

Extracted  from  the  Cacao  Theobroma  in  the  form  of  a 
whitish  semi-solid  grease.    The  beans  yield  nearly  forty  per 


124  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


cent,  of  oil,  finding  application  in  pharmacy  as  a  vehicle  for 
applying  many  drugs,  and  in  perfumery  for  cosmetics.  For 
soap  it  has  not  been  largely  used,  though  it  would  make  a 
superior  soap  for  toilet  purposes. 

Carapa  Oil, 

or  vateria  tallow,  is  the  product  of  the  kernel  of  a  species  of 
personia,  a  palm-tree,  met  with  in  Bengal  and  Coromandel. 
It  is  of  a  bright  yellow  color,  and  known  as  pine  tallow. 

Malabar  Tallow, 

obtained  from  the  fruit  of  the  Vateria  indica^  is  a  white,  wax- 
like tallow,  melting  at  85^  C.  (95°  F.) ;  it  is  natural  to 
Mozambique,  and  but  little  known  in  Europe  or  the  United 
States. 

GoA  Butter, 

a  fat  from  the  seed  of  Brindonica  Indica^  is  used  by  the 
natives  as  butter.  It  is  white,  of  pleasant  taste,  and  melts  at 
40^  0.  (104°  F.) ;  it  is  also  used  in  medicine. 

Grape-seed  Oil. 

The  seeds  from  wine  lees  yield  about  10  or  12  per  cent,  of 
a  pale-yellow  oil  that  might  be  utilized  for  soap.  It  is  now 
used  in  the  countries  of  production  as  a  table  oil. 

Oil  of  Tobacco  Seeds 

has  been  used  for  various  purposes.  It  is  perfectly  bland, 
and  resembles  poppy-seed  oil. 

Oil  of  Belladonna  Seeds 

is  similar  to  that  from  the  tobacco  seeds,  and  is  used  in  some 
parts  of  Germany  as  a  lamp  oil. 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS. 


125 


Waxes. 

Beeswax. — Wax  is  tlie  siibatance  secreted  by  the  bee,  an 
insect  belonging  to  tbe  family  of  the  Mellifica^  order  of  tlie 
Hymenoptera.  As  it  exists  in  the  combs  and  after  purifica- 
tion, wax  is  a  solid  fatty  body,  compact,  of  a  yellow  color, 
more  or  less  dark,  insoluble  in  water,  soluble  in  fixed  oils,  in 
20  per  cent,  of  boiling  alcohol  and  ether,  and  in  spirit  of  tur- 
pentine ;  it  has  no  taste;  its  odor  is  aromatic  and  similar  to 
that  of  honey.  Wax  is  dry,  not  greasy,  to  the  touch,  tena- 
cious, yet  brittle.  Yellow  wax  melts  at  62°  C.  (143.6°  F.) 
to  63°  C.  (145.4°  F.).  Its  sp.  gr.  is  0.9750.  It  burns  without 
leaving  any  residuum. 

There  are  two  kinds  of  wax,  the  yellow  wax.,  the  properties 
of  which  we  have  just  described,  and  the  white  wax^  which  is 
the  bleached  yellow  wax.  The  white  wax  is  obtained  by 
melting  the  yellow  wax  and  reducing  it  to  thin  plates,  like 
ribbons,  and  exposing  them  to  the  sun  and  air  for  several 
days,  until  perfectly  white.  It  is  white,  slightly  diaphanous 
when  thin,  without  taste,  nearly  without  odor,  hard  and 
brittle  at  0°  0.  (32°  F.),  and  very  malleable  at  30°  C.  (86° 
F.);  it  becomes  softer  when  heated  ;  at  65°  C.  (149°  F.)  it  is 
completely  liquid,  but  it  cannot  be  boiled  without  decompo- 
sition. 

Like  yellow  wax,  it  is  insoluble  in  water,  partly  soluble  in 
alcohol,  but  dissolves  very  well  in  ether  and  in  fixed  and 
essential  oils.  Its  sp.  gr.  is  from  0.960  to  0.966.  Its  frac- 
ture is  slightly.,  granular ;  it  sticks  to  the  fingers  when 
kneaded ;  it  is  inflammable,  and  burns  with  a  white  flame 
without  leaving  a  residuum.  Beeswax  has  but  little  appli- 
cation for  soaps,  though  it  is  customary  to  add  a  little  to  the 
finest  soap  to  improve  its  appearance  and  consistency. 

Palm-tree  Wax.  —  Produced  by  the  Ceroxylon  andicola^ 
which  is  very  abundant  in  Kew  Granada.  It  is  obtained  by 
scraping  the  epidermis  of  the  tree.  The  scrapings  are  then 
boiled  in  water,  and  the  wax  floats  on  the  surface  without 
melting.  In  a  crude  state  it  has  the  form  of  a  gray-white 
powder.    Purified  by  treatment  with  boiling  w^ater  and 


126  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


alcohol,  it  is  yellowish-wbite,  but  slightly  soluble  in  boil- 
ing alcoliol,  and  precipitates  by  cooling.  It  melts  at  72°  C. 
(161.6°  R). 

Carnauba  Wax  is  produced  by  a  palm  tree  which  grows 
abundantly  in  the  provinces  of  the  north  of  Brazil.  To  ob- 
tain it,  the  leaves  are  cut  and  dried  in  the  shade,  and  soon 
the  wax  is  separated  in  the  form  of  thin  scales  which  are 
melted.  This  wax  is  soluble  in  boiling  alcohol  and  in  ether  ; 
])y  cooling  it  crystallizes  ;  it  melts  at  88.5°  C.  (191.3°  F.) ; 
it  is  very  brittle,  and  is  easily  reduced  to  powder. 

Myrtle  Wax  is  obtained  by  boiling  in  water  the  berries  of 
sevenil  si)ecies  of  Myrim^  especially  the  Myrica  cerifera^  a  tree 
very  common  in  the  Southern  States.  These  berries  give  25 
per  cent,  of  their  weight  of  wax.  The  crude  wax  is  green 
and  may  be  saponified.  Purified  by  treatment  with  boiling 
water  and  cold  alcohol,  this  wax  is  greenish-yellow,  and  melts 
at  47.5°  C.  (117.5°  F.). 

Ocuba  Wax  is  obtained  from  a  Myn'stica  in  the  province  of 
Para,  and  in  French  Guiana.  This  tree  produces  a  fruit  with 
a  stone  covered  with  a  thick  crimson  pellicle,  which  colors 
water  red.  To  extract  the  wax,  the  stones  are  crushed, 
reduced  to  a  pulp,  and  boiled  for  some  time  with  water ;  the 
wax  floats  on  the  surface.  This  wax  is  yellowish-white, 
soluble  in  boiling  alcohol,  and  fusible  at  36.4°  C.  (97.7°  F.). 

The  wax  of  bicuycla,  obtained  from  the  Myristlca  bicuyda^  is 
yellowish-white,  soluble  in  boiling  alcohol,  and  melts  at  35° 
C.  (95°  F.).    It  is  but  little  known  to  commerce. 

Rosin  or  Colophony. 

With  the  name  rosin"  we  designate  a  group  of  bodies 
which  appear  in  nature  solid,  brittle,  and  again  in  semi-solid 
substances;  they  are  not  soluble  in  water,  but  soluble  in 
ether,  alcohol,  and  sulphuret  of  carbon,  they  are  rich  in  carbon, 
poor  in  oxygen,  and  free  from  nitrogen,  and  burn  with  a 
fuliginous  flame.  I^one  of  the  rosins  are  a  chemical  elemen- 
tary body,  but,  like  all  immediate  matters  furnished  by  the 
plant,  a  complicated  mixture  of  substances.    The  integral 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  127 


coraponeiits  of  rosin  are  the  resinous  acids,  carbonate  con- 
taining substances,  which  eject  from  carbonate  of  alkalies 
the  carbon,  and  combine  with  the  alkalies.  Besides  the 
abietic  acids  there  are  in  the  natural  rosins  volatile  oils, 
gums,  often  cinnamonic  acid  and  benzoic  acid. 

They  are  divided  into  three  principal  groups:  1st,  common 
rosins ;  2d,  balsams  ;  and  3d,  gum  resins.  The  latter  are  dis- 
tinguished from  the  common  rosins  by  their  contents  of  gum. 
The  balsams  are  generally  solutions  of  rosins  in  volatile  oils, 
or  mixtures  of  volatile  oils  and  rosin. 

That  the  resins  belong  to  the  most  extensive  vegetable 
substances,  is  well  known,  and  has  been  proved  by  numerous 
chemical  experiments  and  investigations.  These  substances 
have  been  found  in  all  classes  of  the  vegetable  kingdom,  yea, 
even  in  the  tissues  of  the  fungi;  also  in  all  organs  of  plants, 
and  in  all  known  vegetable  tissues  their  presence  has  been 
proved.  All  resinous  matters  are  products  of  a  so-called 
regressive  metamorphosis  of  matter. 

Notwithstanding  the  extraordinary  distribution  of  the 
resins  in  the  vegetable  kingdom,  the  number  of  the  plants 
which  furnish  applicable  resins  is  proportionately  small,  and 
the  number  of  the  families  to  which  these  plants  belong  is 
also  relatively  limited.  For  soap  manufacturers  only  that 
rosin  has  interest  which  is  furnished  by  most  of  the  Fbrus 
species,  and  is  presented  in  commerce  under  the  name  of 
common  rosin  or  colophony. 

The  balsams  of  the  abies^  hence  of  the  pines,  firs,  etc.,  are 
called  turpentines.  They  originate  partly  in  the  bark,  partly 
in  the  young  wood  of  the  trees.  In  the  bark  it  seems  to  be 
prevalent  in  the  pith,  /.  g.,  the  starch  grains  which  are  in- 
closed in  the  pith  of  the  resinous  fibres;  while  in  the  wood 
substance  it  appears  to  be  the  parenchyma  which  furnishes 
the  material  for  the  formation  of  rosin.  The  rosin,  or  bal- 
sam, ducts  of  the  abies^  wherein  the  turpentine  often  gathers 
in  masses,  and  is  conducted  outside  or  to  the  wood  substance, 
is  found  in  all  the  trees  of  this  family.  They  appear  least  in 
the  bark,  frequently  though  also  in  the  wood  substance,  and 


128 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


originate  either  by  transformation  of  entire  tissue-cords  or 
by  separation  of  the  res^iiration  tissues. 

Turpentine  is  the  origin  of  the  productions  known  as  oil 
of  turpentine,  pine-tree  rosin,  black  pitch,  and  colophony, 
and  is  especially  produced  in  ]^orth  America  and  Europe. 
The  resin  is  either  accidentally  exuded,  or  the  yield  of  rosin 
is  the  object  of  a  planned  operation  of  the  rosin  scraper  or 
pitch  maker,  whereby  the  rosin  is  caused  to  flow  from  the 
trees  by  intentional  incisions  in  the  same. 

The  turpentine,  which  flows  spontaneously  from  the  trees 
and  is  dried  by  the  atmosphere,  contains  but  little  oil ;  while 
the  fresh  exuded  oil,  on  the  other  hand,  contains  almost  all  of 
its  oil.  If  the  turpentine  is  distilled  with  water,  the  oil  passes 
over,  and  a  rosin  mass  remains  as  a  residue,  the  "  boiled  tur- 
pentine." If  rosin  is  melted  without  w^ater,  until  it  becomes 
clear,  then  the  colophony  or  rosin  remains.  All  rosins  desti- 
tute of  oil,  originating  from  turpentine,  either  by  sponta- 
neous exudation,  or  by  distillation  of  the  volatile  oils,  are 
as  common  rosins,  despite  their  dift'erence  of  origin,  brought 
into  one  category,  namely,  the  pine-tree  rosin. 

Up  to  the  most  recent  period,  it  has  been  endeavored 
to  prove  the  existence  of  several  different  abietic  acids  in 
rosin,  i.  e.,  an  amorphous  combination,  pinic  acid  (C^pH^oOJ, 
and  another  crystallizing  in  rhombic  prisms,  thesylvinic  acid 
(C^pH^oOJ.  According  to  Streaker  the  first  is  . only  the  amor- 
phous modification  of  the  latter.  According  to  the  investi- 
gations of  Laurent,  French  turpentine  is  said  to  contain  a 
combination  of  great  afllinity  with  sylvinic  acid,  w^hich  he 
called  pimar  acid  ;  and,  according  to  Unverdorben,  there  is 
in  colophony  a  specific  abietic  acid,  which  originates  from 
the  sylvinic  acid  by  heating,  viz.,  colopholic  acid.  But  in 
opposition  to  this  are  the  investigations  of  Maly,  who  in 
turpentine,  in  fir-tree  rosin,  and  in  colophony  proves  but  one 
acid,  to  wit,  the  abietic  acid  (C^^H^^O^),  which  in  the  sub- 
stances named  appears  either  as  such,  or  is  substituted  by  its 
anhydrite.  The  resinous  trees  form  the  anhydride.  If  this 
is  exposed  to  the  air,  it  is  transformed  by  absorption  of  water 
into  abietic  acid.    By  melting  the  always  crystallizing  acid 


MATERIALS  USED  IN  THE  MANUFACTURE  OF  SOAPS.  129 

changes  into  its  amorphous  anhydrid.  Fir-tree  rosin  contains, 
therefore,  according  to  Maly,  abietic  acid  ;  colophony,  on  the 
other  hand,  its  anhydrid.  The  amorphous  substance  of  the 
fir  rosin  is  soluble  in  72  per  cent,  of  alcohol.  It  is  an  indif- 
ferent substance.  It  was  formerly  termed  the  gamma  rosin 
or  turpentine,  in  contradistinction  to  the  two  acidy  combina- 
tions of  the  pine-tree  rosin,  which  were  formerly  called 
alpha  and  beta  rosins. 

Besides  its  application  in  the  fabrication  of  soap,  common 
rosin  finds  varied  uses.  The  most  important  of  these  em- 
ployments are  the  manufacture  of  varnishes,  lacquer,  cements, 
brewers'  and  bottlers'  pitch,  and  for  lubricating  wagons  and 
machinery. 

For. the  purposes  of  soap-making  it  is  sometimes  desirable 
to  have  a  very  light  rosin.  This  may  be  attained  by  artifi- 
cial bleaching.  The  rosin  is  melted  in  a  kettle  and  allowed 
to  settle  until  all  dross  has  gathered  on  the  bottom,  which  is 
performed  in  about  half  an  hour.  The  clear  rosin  is  scooped 
over  into  another  kettle,  and  to  each  100  pounds  of  it  20 
pounds  of  salt  solution  of  9°  B.  are  added.  This  entire  mass 
is  left  boiling  for  one  hour,  when  the  fire  is  diminished.  As 
soon  as  the  boiling  ceases,  the  rosin  settles  upon  the  bottom, 
and  the  salt  lye  separates  as  a  brownish  fluid  on  the  surface. 
This  salt  lye  is  ladled  out,  the  salt  water  renewed,  and  again 
boiled.  If  the  rosin  is  not  yet  sufficiently  discolored,  the 
operation  is  repeated  for  the  third  time. 

Rosin  is  employed  as  well  in  the  fabrication  of  hard  as 
of  soft  soaps;  but  never  worked  up  alone,  always  in  conjunc- 
tion with  some  fats.  Soap  of  pure  rosin  never  becomes  solid, 
but  even  for  a  soft  soap  it  cannot  be  applied  alone,  inasmuch 
as  it  never  attains  the  peculiar  consistency  which  is  expected 
of  a  good  soft  soap. 


9 


130  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


SECTIOKIY. 

THE  RECOVERY  OF  OFFAL  AND  OTHER  REFUSE  FATS  AND 

GREASES. 

It  is  a  peculiarity  of  raodern  times,  that  science  and  in- 
dustry are  constantly  endeavoring  to  utilize  otherwise  useless 
and  rejected  ottal  and  refuse  matters  for  various  objects.  This 
is  a  gain  which  should  be  all  the  more  prominent,  since  it  ad- 
vances the  national  welfare,  and  also  aids  in  the  removal  of 
such  matters  which,  having  become  putrefied,  infect  the  air 
with  poisons  which  are  often  the  cause  of  disease  and  epi- 
demics. In  the  vicinity  of  large  cities,  establishments  which 
attend  in  a  rational  manner  to  working  up  and  utilizing 
the  offal  of  organic  nature,  are  a  great  blessing.  Thus  Paris 
has  in  its  environs  such  manufactories  on  a  grand  scale.  The 
largest  and  most  important  of  them  is  the  one  of  Soutfrice  & 
Co.,  at  St.  Denis.  It  would  be  very  interesting  to  state  here 
what  a  variety  of  things  are  manufactured  in  that  estab- 
lishment. In  the  year  1862  they  began  to  utilize  the  rem- 
nants and  the  offal  from  the  slaughter-houses,  from  which 
they  drew  a  yearly  yield  of  120,000  francs  ($24,000).  The  year 
following  they  gave  their  attention  to  the  scum,  dross,  and 
dregs  of  the  river  Seine.  In  consideration  of  the  vast  advan- 
tages which  this  undertaking  would  have  on  the  state  of  the 
public  health,  the  Prefect  of  the  Seine  granted  to  this  firm, 
for  a  nominal  revenue,  the  sole  yield  accruing  from  the  work 
of  clearing  the  river  of  cadaverous  and  floating  fats,  as  well 
as  other  stuffs  injurious  to  health.  In  December,  1864, 
Souffrice  &  Co.  undertook  the  removal  of  the  putrid  waters, 
the  sweepings  imd  the  vegetable  remnants  from  tw^enty-flve 
public  institutions  of  Paris.  The  vegetable  refuse  was  puri- 
fied by  steam,  and  used  for  feeding  hogs.    In  this  way  the 


RECOVERY  OF  REFUSE  FATS. 


131 


firm  mentioned  was  enabled  to  fatten  3000  hogs  per  annum. 
In  December,  1867,  they  constructed  two  distilling  appara- 
tuses for  the  manipulation  of  the  black  residues  of  the  refined 
rape-seed  oil,  and  obtained  thereby  an  annual  production  of 
500,000  pounds  of  pure  sebacic  acids,  w^hich  are  a  suitable  in- 
gredient for  the  manufacture  of  soaps.  They  furthermore 
purchased  from  the  railway  companies  the  old  wheel  grease, 
to  obtain  the  fat  contained  therein,  and  paid  for  it  annually 
100,000  francs  ($20,000).  Besides  the  fats  and' sebacic  acids, 
the  chief  product  of  the  establishment  is  an  azotic  fertilizer. 
Of  this,  thousands  of  tons  are  annually  manufactured. 

The  Yield  of  Offal  Fats  by  means  of  Sulphuret  of  Carbon. 

For  the  recovery  of  fat  from  refuse  matter  the  introduc- 
tion of  sulphuret  of  carbon  has  wrought  a  great  service, 
since  by  its  aid  it  has  become  possible  to  extract  fat  from 
such  substances  as  contain  but  small  portions  of  it,  and 
which  by  further  pressing  will  no  longer  yield  it.  Some  time 
ago  Deiss  had  his  aim  directed  to  it, and  applied  the  sulphuret 
of  carbon  in  the  manner  indicated.  Thus  he  extracted  fat 
from  the  black  tar-like  residues,  which  are  yielded  by  the 
distillation  of  fats  in  the  stearine  manufactories,  from  the 
sawdust  which  had  served  for  the  filtering  of  oil,  from  the 
dirty  remnants,  which  were  formed  by  refining  the  oils  with 
sulphuric  acid,  from  wagon  grease,  and  from  oily  polishing 
rags. 

The  residuum  of  the  distillation  of  fat  which,  by  a  faulty 
saponification,  often  contains  upwards  of  twenty  per  cent,  of 
fat,  must,  before  the  treatment  with  sulphuret  of  carbon,  be 
mixed  with  sawdust  in  order  to  enhance  the  filtration  of  the 
dissolved  fat. 

The  sediment  from  the  treatment  of  oils  with  sulphuric  acid 
often  contains  fifty  per  cent,  of  sebacic  acid.  In  order  to  gain 
this  the  residuum  is  treated  by  washing  out  the  sulphuric 
acid  with  hot  water,  then  dried,  mixed  with  sawdust  and 
extracted.    The  sawdust,  which  is  used  for  filtering  oil,  still 


132  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


yields  with  sulphuret  of  carbon,  even  after  being  pressed  as 
much  as  possible,  a  farther  15  to  18  per  cent,  of  oil. 

The  old  wagon  grease  is  first  treated  with  sulphuric  acid, 
then  washed  and  dried  and  finally  extracted.  Fatty  rags 
are,  without  any  further  manipulation,  at  once  treated  in 
sulphuret  of  carbon.  This  treatment  has  a  threefold  advan- 
tage: the  gaining  of  the  fat,  cleansing  of  the  rags,  so  that 
they  may  again  be  used,  and  averting  great  danger  of  fire, 
which  originates  frequently  from  spontaneous  combustion  in 
heaping  up  these  oily  rags  in  the  work-rooms. 

For  all  the  above  mentioned  purposes  benzine  might  also 
be  used  in  lieu  of  sulphuret  of  carbon,  but  the  latter  has  the 
advantage  of  possessing  a  greater  poAver  to  dissolve  fats.  Be- 
sides this,  it  should  be  noticed  that  oftals,  which  have  been 
lying  in  dampness,  and  contain  glutinous  fat,  cannot  be 
worked  up  with  benzine,  while  worked  with  sulphuret  of 
carbon  they  furnish  good  results. 

Wool-fat  and  Fuller's-fat. 

Already  in  the  second  decade  of  this  century,  Kurrer,  von 
Westrumb,  and  others,  had  drawn  attention  to  the  fact  that 
immense  quantities  of  fat  were  lost  from  the  washing  vats  of 
the  cloth  manufactories,  spinning  establishments,  dyeing  fac- 
tories, etc.,  and  they  recommended  that  these  losses  be  re- 
deemed. In  the  washing  of  the  wool  must  also  be  estimated 
the  sebacic  acid,  which  the  not  unimportant  quantity  of  soap 
furnishes,  and  is  requisite  for  the  process  of  scouring,  as  well 
as  the  comparatively  high  amount  of  the  wool  yolk  or  suint. 
The  oldest  method  for  the  utilization  of  the  fatty  substances  of 
the  soap  waters,  consisted  in  leading  the  water  running  from 
the  washing-tubs  into  especial  cisterns,  mixing  it  there  with 
milk  of  lime,  then  letting  it  settle  until  it  had  cleared  off. 
After  removing  the  liquid  above,  the  slimy  sediment  was 
taken  out,  strained  through  coarse  canvas  for  removing  the 
sand,  hair,  etc.,  and  well  dried.  The  slime  having  assumed 
a  doughy  consistency,  it  was  straightened  out  into  pieces 
of  the  size  of  half  a  brick,  and  dried  in  the  air.    The  dry 


Hecovery  of  refuse  fats 


133 


pieces,  called  "  suinter,"  from  the  French  word  "  suint" 
(wool-sweat)  were  then  dried  in  retorts,  for  the  fabrication 
of  illuminating  gas.  This  manufacture  of  sidnter,  as  simple 
as  may  appear  its  manipulations,  requires  great  space  and 
appointments.  The  drying  of  the  limy  fat  masses,  which 
can  only  be  accomplished  in  thin  layers,  proceeds  in  damp 
weather  but  slowly,  and  is  during  the  winter  season  only 
manageable  in  artificially  warmed  and  ventilated  localities. 
To  this  must  yet  be  added,  the  slow  settling  of  the  fatty 
masses,  but  loosely  combined  with  lime,  and  the  difficulty, 
on  account  of  the  ever  varying  amount  of  fat  of  the  soap- 
water,  to  guess  the  right  proportion  of  the  precipitation. 
Either  too  much  or  too  little  lime  may  be  applied,  and  hence 
sufler  in  the  first  case  disadvantage  for  the  fabrication  of 
illuminating  gas,  in  the  latter  case  great  loss  of  the  sebacic 
acid.  For  this  reason  this  method  of  fabrication  has  been 
abolished,  and  the  fat  is  at  present  gained  from  the  rinsing 
waters  by  decomposing  the  same  with  sulphuric  acid.  A 
compact,  creamy  mass  is  separated,  which  is  mainly  composed 
of  sebacic  acids,  and,  according  to  its  respective  origin,  is 
either  called  wool-fat  or  fuUer's-fat.  By  the  first  appellation 
is  designated  the  fat  obtained  from  the  offal  liquids  of  the 
wool-washing  establishments,  while  the  soap-waters  of  the 
cloth  manufactories,  dyers'  establishments,  etc.,  furnish  the 
fuller's-fat.  From  the  suint,  potash  is  now  obtained  in 
France  in  paying  quantities. 

For  recovering  these  offal  fats,  the  following  process  is 
pursued :  The  soap-water  is  put  into  reservoirs  of  pine  wood. 
Such  a  reservoir,  which  is  2.70  metres  (8.85  feet)  long,  1.73 
metres (5.57  feet)  wide,  and  1.57  metres  (5.15  feet)  deep,  holds 
up  to  the  filling  level  7000  litres  (1849  gallons).  Sulphuric 
acid  is  added,  and,  in  order  to  hasten  the  separation,  steam 
is  admitted  for  a  period  of  from  one  to  two  hours.  The 
use  of  sulphuric  acid  depends,  as  is  self-evident,  on  the 
amount  of  alkali  contained  in  the  soap-water;  but  a  little 
surplus  is  always  allowed,  since  by  it  a  quicker  and  more 
complete  separation,  and  in  consequence  thereof  a  more  solid 
refined  mass  is  obtained.    On  an  average  50  pounds  of  sul- 


184 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


phuric  acid  of  66°  B.  are  sufficient  for  a  complete  separation 
of  7000  litres  of  soap-water,  and  furnish  390  to  410  pounds, 
on  an  average ;  hence  400  pounds  of  fat  substance,  accord- 
ing as  this  is  allowed  time  to  drop  off  into  the  filtering  basins. 
The  filtering  vessels  consist  of  baskets,  which  are  filled  with 
coarse  hemp  cloth.  When  now  the  caseous  doughy  mass 
is  amply  drained  of  water,  by  filtration,  and  has  reached  the 
requisite  plastic  consistency  necessary  for  forming  it  into 
pressed  cakes,  it  is  wrapped  up  in  hemp  cloths,  and  in  the 
usual  way  laid  between  plates  in  a  hydraulic  press,  and,  at 
first  cold,  somewhat  later  with  admission  of  steam,  pressed 
until  the  complete  exhaustion  of  the  liquid  contents  is 
reached.  In  the  press  cloths  remains  thereby  a  solid  residuum 
about  one-half  of  the  mass  w^hich  had  been  taken,  while 
an  equal  mass  of  watery  fat  runs  into  the  reservoir.  The 
latter  quantity  reduces  itself  likewise  by  the  various  opera- 
tions of  the  refining  process  to  one-half  of  its  weight,  where- 
by a3neld  of  25  per  cent,  of  salable  wool-fat  from  the  pressed 
mass,  ^.  7.1  grammes  (0.25  oz.)  per  litre  (2.1  pints)  soap- 
water  may  be  accepted  as  the  mean  value  of  fabrication. 

The  crude  aqueous  fat  contained  in  the  press  reservoirs  yet 
needs  the  purifying  and  draining  of  water.  For  the  purpose 
of  purifying,  the  fat  is  placed  in  iron  tanks  of  3J  feet  diam- 
eter and  5  feet  in  height,  which  are  inserted  into  iron  hous- 
ings. According  to  the  greater  or  lesser  purity  of  the  fat 
the  fifth  or  fourth  part  of  its  volume  of  water  and  from  2  to 
3  per  cent,  of  its  weight  of  sulphuric  acid  of  66°  B.  are  added, 
and  heated  by  a  direct  introduction  of  steam  to  a  moderate 
boiling,  and  kept  up  for  one  hour.  Thereupon  the  steam 
is  cut  ofi",  the  mass  allowed  to  settle  for  a  few  hours,  and 
then  the  lower  dull  and  slimy  stratum  is  drawn  ofi'.  The 
liquid  drawn  ofit'  is  replaced  by  a  like  quantity  of  pure  water, 
and  with  it  boiled  up  moderately  in  order  to  remove  the 
sulphuric  acid  traces.  i^Tow  the  whole  is  allowed  to  deposit, 
and,  after  removing  the  watery  stratum,  the  clear  mass  of  fat 
is  then  drawn  ofi*.  The  fat  thus  gained  is  still  very  aqueous. 
For  removing  the  water  the  fat  is  put  into  kettles  in  which 
pipes,  either  of  iron  or  copper,  and  of  a  spiral  shape,  are 


RECOVERY  OF  REFUSE  FATS. 


135 


placed,  and  through  these  serpentine  pipes  the  steam  vapors 
circulate  and  evaporate  the  water. 

Frequently  the  wool-fat  is  bleached  before  draining,  be- 
cause it  receives  a  better  appearance,  and  thereby  a  corre- 
spondingly increased  commercial  value,  and  IS,  moreover? 
freed  from  its  disagreeable  smell.  The  bleaching  is  performed 
in  wooden  vats,  which  are  lined  inside  with  lead,  and  pro- 
vided with  a  stirring  apparatus  as  well  as  with  a  heating 
serpentine.  The  bleaching  liquid  is  composed  of  a  solution 
made  acid  by  sulphuric  acid  and  chromate  of  potash — 3 
parts  of  sulphuric  acid  of  66°  B.  to  one  part  of  chromate  of 
potash — of  which,  in  most  cases,  a  small  quantity  produces 
the  desired  result.  In  the  first  place  the  deoxidized  fat  is 
placed  in  the  vat  while  it  is  yet  warm,  and  heated  while  the 
diluted  acid  is  added  under  constant  stirring  (in  small  por- 
tions) on  account  of  the  ensuing  ebullitions  of  the  chromate 
of  potash,  which  is  to  be  diluted  in  threefold  its  weight  of 
water.  The  temperature  must  during  the  entire  operation — 
which  lasts  one  hour  and  a  half — not  exceed  56°  C.  (132.8°  F.). 
After  standing  several  hours  the  bleached  fat  mass  settles 
on  the  surface.  Thereupon  the  watery  salt  containing  liquid 
is  removed,  w^ashing  the  fat  afterwards  with  pure  water,  and 
after  the  removal  of  the  wash-water  the  stratum  of  fat  is 
taken  ofiT,  which,  by  heating  with  indirect  steam,  is  then 
freed  from  water. 

If  fuller's-fat  is  heated  and  permitted  slowly  to  cool  off  in 
vessels,  a  separation  of  a  solid  and  liquid  mass  takes  place. 
In  order  to  attain  this  the  fat  is  heated  to  75°  C.  (167°  F.), 
placed  in  large  vats  of  2|  to  3  feet  diameter,  and  6  to  10  feet 
high,  and  its  temperature  slowly  decreased  to  9  to  12°  C.  (48.2 
to  53.5°  F.).  To  attain  the  most  perfect  separation  possible, 
the  cooling  off  must  be  effected  very  gradually,  otherwise 
the  solid  sebacic  acids  are  only  kept  suspended  in  the  liquid 
mass  as  a  curd,  w^iich  is  difficult  to  separate  from  the  liquid 
mass.  By  a  careful  operation  the  sebacic  acids  separate  on 
the  sides  and  bottom  of  the  vat  in  crystals.  The  liquid  part 
may  be  drawn  off  by  means  of  a  spigot  in  the  bottom  of  the 
vat.    The  solid  masses  are  then  pressed  out  in  order  com- 


136  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

pletely  to  remove  the  oily  part.  Such  a  process  of  separation 
requires  in  the  summer  season — in  case  a  cool  cellar  is  not  at 
disposal — from  three  to  four  weeks;  during  intense  winter 
coldness  it  may  become  necessary  to  surround  the  vessels  for 
crystallization  with  non-conductors  of  heat,  thus  to  delay 
the  cooling  off.  The  liquid  fat  which  is  drawn  off  is  called 
wool-fat  train. 

The  value  of  the  pressed  residuum,  as  noted  above  is  equal 
to  50  per  cent,  of  the  weight  of  the  mass,  and  it  may  be  stated 
that  carefully  mixed  samples  of  different  pressings  in  the 
manufacturing  business  result  in  the  following  composition  : 


Water  10.66 

Fatty  substances   .  84.7^ 

Other  organic  matters  22.37 

Fine  sand  30.33 

Soluble  silicate  0.08 

Sulphuric  acid       .       .       .       .       .       .  .0.28 

Phosphoric  acid  .0.09 

Oxide  of  iron  and  clay  0.99 

Lime  0.25 

Magnesia  0.10 

Alkalies  0.12 


100.00 

According  to  this,  this  material  is  very  well  suited  for 
manufacturing  illuminating  gas  on  account  of  its  great  value 
in  fat  and  other  organic  matter,  of  which  the  former  fur- 
nishes per  pound  9,  the  latter  7,  cubic  feet  of  illuminating  gas. 
Since  100  pounds  of  gas-coal  give  on  an  average  500  cubic 
feet  of  illuminating  gas,  and  8  cubic  feet  of  wool-fat  gas  have 
a  lighting  capacity  of  at  least  10  cubic  feet  of  coal  gas,  there 
will  be  no  error  in  considering  the  press  cakes  as  of  equal 
value  with  good  gas  coal,  especially  if  all  other  accessory  cir- 
cumstances are  taken  into  consideration. 

Inasmuch  as  in  the  pressed  residuum,  which  represents  50 
per  cent  of  the  mass,  34.74  per  cent,  fat  substances  are  con- 
tained, therefore  17.37  per  cent,  of  the  total  fat  value  of  the 
manufacturing  material  have  only  a  secondary  value;  hence 
the  method  just  described  is  yet  a  very  faulty  one  and  capa- 
ble of  improvement.    Vohl  has  therefore  proposed  to  mix 


RECOVERY  OF  REFUSE  FATS. 


137 


the  soap-water  with  chloride  of  calcium,  and  to  decompose 
the  lime-soap  thus  produced  by  muriatic  acid.  He  operates 
as  follows : — 

The  soap- water  is  mixed  with  an  aqueous  solution  of  chlo- 
ride of  calcium  as  long  as  a  caseous  precipitate  ensues.  The 
lime-soap  thus  formed  is  separated  by  straining  by  means  of 
large  baskets,  which  are  lined  with  hemp  cloth  (not  too 
coarse),  and  then  freed  by  letting  drop  off  and  pressing  out 
the  greater  part  of  the  water  contained  therein.  The  mass 
drained  of  its  water  is  then  placed  in  well-covered  vats  of  12 
feet  high  and  4 J  feet  wide,  and  decomposed  therein  with  a 
corresponding  quantity  of  muriatic  acid,  which  is  as  free  as 
possible  from  sulphuric  acid.  By  a  direct  introduction  of 
steam  the  decomposition  is  accelerated,  and  the  separated 
sebacic  acid  kept  liquid.  The  gases  which  during  the  de- 
composition of  the  infused  steam  vapors  are  developed,  pass 
through  a  cooling  worm  of  cast  iron,  which  empties  into  a 
tightly  closed  iron  box.  The  latter  contains  slaked  lime, 
and  is,  by  means  of  a  pipe  conduit,  connected  with  the  heat- 
ing apparatus  of  the  steam-boiler.  By  this  apparatus  all 
noxious  gases  and  vapors  are  completely  destroyed.  After 
the  decomposition  of  the  lime-soap  has  been  completely 
effected,  the  mixture  is  left  for  six  hours  to  rest,  and  then,  by 
means  of  a  spigot  in  the  bottom  of  the  vat,  the  solution  of 
chloride  of  calcium  is  drawn  off,  w^hich  in  turn  is  again 
applied  for  a  new  precipitation.  The  fat  mass  is  now  again 
mixed  with  one-half  of  the  quantity  of  diluted  muriatic  acid 
of  the  proportion  used  for  decomposition,  and  for  one-half 
to  three-quarters  of  an  hour  steam  is  again  passed  through. 
Thereupon  the  steam  is  cut  off'  and  the  entire  mass  is  left  at 
rest.  Three  strata  have  now  formed,  one  lower  aqueous 
sour  liquid,  one  upper  clear  stratum  of  fat,  and  one  middle 
emulsion-like  stratum,  consisting  of  fat  and  diluted  acid. 
The  clear  diluted  acid  is  now  drawm  off,  without,  however, 
allowing  the  emulsive  stratum  to  pass  off'  with  it.  The 
emulsion  causes  great  difficulty  in  the  separation  of  the 
sebacic  acids  from  the  watery  liquid. 

The  sebacic  acids  are  then  either  freed  from  water,  and  at 


138 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


once  brought  into  the  trade,  or  they  are  previously  bleached. 
For  draining  off  the  water  the  emulsified  oil  stratum  is  either 
heated  by  the  addition  of  culinary  salt  over  an  open  fire  (in 
case  of  a  common  kind  of  fat),  or  (for  better  sorts  of  fat)  with 
indirect  steam.  This  latter  mode  of  heating  is  applied  espe- 
cially when  the  soap-waters  originate  from  the  scouring  or 
boiling  of  silk,  or  from  Turkey-red  (Adrianople  red)  dyeing 
establishments;  hence  in  greater  part  being  the  result  of 
olive-oil  soap. 

For  bleaching  purposes  a  solution  of  sulphuric  acid  mixed 
with  chromate  of  potash  is  used.  When  separated  and 
washed,  the  yet  warm  sebacic  acids  of  the  lime  soap  are 
placed  in  the  vats  (with  the  emulsion  stratum),  and  while 
being  diligently  stirred  the  bleaching  liquid  is  added,  and 
the  mixing  kept  up  for  half  an  hour  longer.  After  resting 
six  hours  the  bleached  sebacic  acids  are,  in  a  great  measure, 
separated ;  the  green  aqueous  liquids  being  drawn  off  they 
are  washed  once  or  twice  with  warm  water.  After  the 
wash  water  has  been  removed  the  oil  emulsion  is  drawn 
ofiT.  The  clear  fat  mass  is  then  at  once  drained  of  water. 
The  emulsive  stratum  is  mixed  with  10  to  lo  per  cent,  of 
canadol  (a  kind  of  benzole),  whereby  an  immediate  separa- 
tion ensues,  and  the  canadol  is  again  separated  by  distillation. 
This  treatment  of  the  emulsified  stratum  with  canadol  takes 
place  only  after  five  or  six  bleaching  operations,  that  is  when 
sufficient  material  has  accumulated  to  fill  a  distilling  appa- 
ratus. The  canadol  regained  can  always  be  used  again  for 
renewed  operations.  In  this  manner  the  sebacic  acids  re- 
covered from  the  silk-scouring  and  Turkey-red  dyeing  estab- 
lishments are  of  a  light  yellowish  color,  and  possess  but  a  faint 
odor. 

Yohl  has  not,  we  are  sorry  to  state,  communicated  the 
results  of  his  experiments,  so  that  a  comparison  between  his 
and  the  usual  method  of  operation  is  impossible.  It  is  known, 
however,  that  chloride  of  alkalies  cannot  be  completely  re- 
moved from  sebacic  acids  by  washing  with  water.  From 
this  fact  reason  is  found  for  objections  to  Vohl's  method. 
Vohl  attempts  to  remedy  this  difficulty  by  the  partial  appli- 
cation of  canadol. 


RECOVERY  OF  REFUSE  FATS. 


139 


The  wool-fat,  as  usually  brought  into  the  market,  is  a 
solid,  tough,  dirty,  yellow-brownish  mass,  which  is  difficult 
to  remove  with  the  spade  from  the  casks  in  which  it  is  packed 
for  transportation.  It  finds  application  in  the  manufacture 
of  soaps,  and  in  the  fabrication  of  lubricators.  For  soap- 
making  it  serves  principally  in  the  preparation  of  rosin 
soap ;  but  soap-boilers  do  not  much  like  to  work  it  on 
account  of  its  inferior  yield,  which  is  explained  by  its  chemi- 
cal composition.  Fuller's-fat  forms  a  thick  oily  mass,  and  is 
a  much  more  valuable  fat,  as  its  price  indicates,  which  is 
quoted  at  about  double  that  of  wool-fat.  It  likewise  finds 
application  chiefly  in  the  fabrication  of  oils  for  lubricating 
and  in  the  manufacturing  of  rosin  soaps.  These  offal  fats 
are  never  by  themselves  used  for  soaps;  but  always  in 
combination  with  other  fats,  particularly  palm  oil  or  tallow, 
and  especially  with  rosin,  saponified.  By  using  these  refuse 
fats  for  lubricating  materials,  it  is  considered  that  they  are 
not  neutral,  but  contain  free  sebacic  acids.  It  is  therefore 
almost  always  more  desirable  to  use  them  for  soap. 

Yohl  in  1867  attempted  to  calculate  the  amount  of  soap  used 
in  the  city  of  Cologne,  and  the  loss  of  fat  caused  thereby,  and 
reached  the  result,  that  that  city,  which  at  that  time  con- 
tained 120,000  inhabitants,  lost  annually  by  the  soap  used 
1,200,000  pounds  of  fat.  This  calculation  extends  only  to 
the  soap  consumed  for  private  purposes.  Establishments  of 
industry,  hospitals,  and  other  public  establishments  are  not 
considered  in  his  calculation,  so  that  the  total  loss  in  fat  is 
really  still  higher.  In  consideration  of  the  large  amounts 
which  this  loss  represents,  and  considering  that  the  products 
of  decomposition  of  the  soap- water,  which  finds  its  way  into 
gutters,  culverts,  etc.,  develop  unwholesome  miasma,  Yohl 
proposed  to  collect  the  soap- waters  even  in  private  residences, 
and  to  deliver  the  same  to  the  respective  manufactories  for 
working  them  up.  This  proposition,  however,  will  for  a  long 
time  to  come  remain  naught  else  but  a  well-meant  desire, 
and  we  must  regard  it  already  as  a  great  progress,  when 
those  who  possess  a  great  quantity  of  refuse  and  offals  con- 
taining an  amount  of  useful  materials,  begin  gradually  to 
utilize  them. 


140 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


SECTIO^s^  Y. 
THE  ADULTERATION  OF  THE  FATTY  BODIES. 

Fats  and  oils  are  subject  to  adulteration  and  falsification, 
particularly  those  of  great  commercial  value,  and  generally 
with  fats  and  oils  of  lower  prices. 

By  exposure  to  the  air  they  absorb  oxygen  and  become 
rancid  ;  some  oils  dry  into  a  kind  of  varnish,  and  are  called 
drying  oils ;  the  fats  are  adulterated  with  foreign  substances 
to  increase  their  weight. 

We  cannot  here  go  into  a  general  analysis  of  all  these  im- 
portant materials,  but  will  examine  such  as  are  in  common 
use  and  most  liable  to  sophistication. 

Olive  Oil. 

Olive  oil  for  the  manufacture  of  soaps  is  ordinarily  adul- 
terated with  cole-seed  oil,  cotton-seed  oil,  and  poppy  oil. 
These  mixtures  are  sometimes  disguised  by  coloring  them 
green  with  indigo,  so  as  to  create  the  impression  that  green 
olive  oil  is  present.  The  adulteration  with  black  poppy  oil 
is  the  most  frequent,  not  only  on  account  of  the  cheapness  of 
this  oil,  but  also  on  account  of  its  sweet  taste,  and  its  odor 
being  but  little  pronounced.  We  shall  see  hereafter  the  pro- 
cess for  detecting  these  falsifications. 

Oil  of  Sweet  Almonds. 

The  oil  of  sweet  almonds  is  principally  falsified  with  poppy 
oil  and  with  sesame  oil.  Several  processes  have  been  pro- 
posed for  detecting  this  falsification. 

Oil  of  sweet  almonds  becomes  cloudy  at  — 20°  C.  (4°  below 


ADULTERATION  OF  THE  FATTY  BODIES. 


Ill 


0°  F.),  find  solidifies  at  —25°  C.  (13°  below  0°  F.),  while 
poppy  oil  begins  to  solidify  between  3.9°  C.  (39°  F.)  and  6° 
C.  (42.8°  F.). 

One  part  of  aqua  ammonia  mixed  with  9  parts  of  oil  of 
sweet  almonds  forms  a  white  soft  soap,  very  smooth  and 
homogeneous,  if  the  oil  be  pure  ;  on  the  contrary,  it  is  clotted 
if  it  contains  more  than  one-fifth  of  poppy  oil. 

Rapeseed  Oil. 

This  oil  is  falsified  with  linseed,  mustard,  and  whale  oils, 
oleic  acid,  etc.  Ammonia  with  pure  oil  gives  a  milk-white 
soap;  and  a  yellowish- white  soap,  when  the  mustard  and 
whale  oils  are  present.  Gaseous  chlorine  colors  rapeseed  oil 
brown,  when  it  contains  whale  oil ;  if  pure,  it  remains  color- 
less. 

Sesame  Oil. 

This  oil  is  ordinarily  mixed  with  earth-nut  oil. 
Linseed  Oil. 

This  oil  is  falsified  with  hempseed  oil,  and  especially  with 
fish  oil.  Pure  linseed  oil  treated  by  hyponitric  acid  becomes 
pale  pink  ;  by  ammonia,  dark  yellow,  and  gives  a  thick  and 
homogeneous  soap. 

Black  Poppy  Oil. 

This  oil  is  often  mixed  with  sesame  and  beech-nut  oils. 
The  pure  oil  is  colored  a  light  yellow  with  hyponitric  acid, 
while  beech  oil  acquires  a  pink  color.  Ammonia  colors  it  a 
light  yellow ;  the  consistency  is  slightly  thick,  and  the  soap 
is  a  little  granular. 

Hempseed  Oil. 

The  adulteration  of  this  oil  is  always  done  with  linseed 
oil.  The  pure  oil  treated  by  ammonia  becomes  yellow,  thick, 
and  granular. 


142 


TECHNICAL  TREATISE  OX  SOAP  AND  CANDLES. 


Castor  Oil 

is  generall}^  mixed  with  black  poppy  oil.  The  adulteration 
is  easy  to  detect  with  alcohol  at  95°  B. ;  a  certain  quantity 
of  oil  agitated  with  this  liquid  is  dissolved  and  leaves  the 
foreign  oil  as  a  residuum. 

Neat's  Foot  Oil. 

This  oil  is  without  doubt  the  most  adulterated  oil  found 
in  commerce;  it  is  mixed  with  whale,  black  poppy  oil,  and 
olein. 

Oleic  Acid. 

This  acid  is  often  mixed  with  rosin  oil.  The  pure  acid, 
treated  with  an  acid  solution  of  nitrate  of  mercury,  yields  a 
pale  straw-colored  foam;  the  rosin  oil  yields  a  very  dark 
orange  foam. 

Palm  Oil. 

This  oil  has  been  mixed  with  or  manufactured  entirely  of 
yellow  wax,  lard,  mutton  suet,  colored  with  turmeric,  and 
aromatized  with  powdered  orris  root,  without  any  genuine 
palm  oil.  By  treating  the  suspected  oil  with  ether,  all  the 
fatty  bodies  are  dissolved ;  the  turmeric  and  orris  root  re- 
main insoluble.  By  saponification  the  mixed  or  artificial  oil 
takes  a  reddish  shade  due  to  the  action  of  the  alkali  on  tur- 
meric. Sometimes  powdered  rosin  has  been  mixed  with  it; 
this  falsification  is  easily  detected  by  treating  the  oil  with 
alcohol :  the  rosin  is  dissolved  while  the  oil  remains  insoluble 

Cocoa-nut  Oil. 

The  commercial  oil  is  often  adulterated  with  mutton  suet, 
beef  marrow,  or  other  animal  greases,  sometimes  also  with 
the  oil  of  sweet  almonds  and  wax.  The  oil  falsified  by  these 
substances  does  not  completely  dissolve  in  cold  ether.  The 
ethereal  solution  is  muddy  like  that  given  by  pure  butter. 


ADULTERATION  OF  THE  FATTY  BODIES. 


143 


The  oil  thus  falsified  has  a  taste  and  an  odor  less  agreeable, 
a  color  rather  grayish  than  yellowish,  and  has  less  consist- 
ency. The  melting  point  is  the  best  method  of  ascertaining 
the  purity. 

Adulterated  with  greases  or  tallows  the  oil  melts  at  26°  to 
28°  C.  (78.8°  to  82.4°  F.);  with  oil  of  sweet  almonds  it  melts 
at  23°  C.  (73.4°  F.). 

ASSAYS  OF  OILS. 

Fatty  oils  are  characterized  by  certain  special  properties, 
by  w^hich  it  is  easy  to  determine  their  purity,  or  to  know  in 
what  proportions  they  are  mixed. 

All  retain  in  solution  substances,  which  become  colored 
under  the  influence  of  certain  chemical  agents.  These  sub- 
stances may  acquire  a  special  coloration  only  by  operating  at 
a  known  temperature.  The  discoloration  is  about  the  same 
if  we  operate  on  oils  of  the  same  kind,  obtained  at  the  ordi- 
nary temperature,  or  at  a  higher  temperature  than  that  of 
the  atmosphere. 

By  old  oils,  we  understand  those  which,  though  prepared 
for  some  time,  have  been  placed  in  good  conditions  of  con- 
servation. Olive  oil,  for  example,  placed  for  one  or  two 
years  in  a  warm  place,  kept  in  a  vessel  half  full,  and  exposed 
to  the  contact  of  the  air,  if  tested  in  a  certain  manner,  is 
colored  like  the  oil  of  sesame.  This  discoloration  indicates 
a  decided  alteration  of  the  substance  it  holds  in  solution. 
This  characteristic  may  be  met  with  in  the  oil  used  in  manu- 
factures, never  in  that  employed  for  food.  The  latter  is 
generally  colorless,  or  very  little  colored.  By  some  other 
modes  of  testing,  this  oil  behaves  like  one  which  has  been 
well  preserved,  or  has  been  recently  obtained. 

Several  authors  have  spoken  of  coloration,  but  their  pro- 
cesses to  produce  these  colorations  are  diflScult ;  besides,  the 
colorations  obtained  are  not  characteristic  enou2:h  to  enable 
us  to  determine  the  purity  of  a  commercial  oil.  We  must 
understand  by  this  name,  the  oil  as  it  is  usually  prepared  in 
the  arts.    The  following  processes  are  easy  of  employment: 


144 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


With  the  oil  tried,  a  coloration  ought  to  he  produced  similar 
to  that  assumed  hy  the  same  kind  of  oil  placed  in  similar 
conditions.  If  there  is  a  mixture,  the  coloration  obtained 
will  be  proportional  to  the  volume  of  each  oil  in  the  mixture. 

We  know  that  fatty  oils  are  formed  of  fatty  acids,  and 
glycerin  ;  that  these  combinations  are  more  or  less  stable 
according  to  the  conditions  of  conservation  of  the  oils ; 
lastly,  that  by  the  nitrogenous  substances  they  contain,  sub- 
stances which  play  the  part  of  a  ferment,  the  glyceric  com- 
binations are  decomposed  into  glycerine  and  fatty  acids. 

If  an  aqueous  solution  of  potash  is  made  to  act  at  the  ordi- 
nary temperature  on  a  rancid  non-siccative  oil,  the  fatty  acids 
set  free  unite  first  with  the  potash  ;  then  the  alkali  has  its 
action  on  the  undecomposed  compounds. 

If  the  same  oil,  but  not  rancid,  is  treated  in  the  same  man- 
ner with  potash,  the  alkali  reacts  at  first  on  the  combinations 
which  in  rancid  oil  are  decomposed  by  the  ferment. 

If  we  treat  a  commercial  oil  at  the  ordinary  temperature 
for  thirty  seconds,  by  a  solution  of  potash,  and  afterwards 
if  this  mixture  is  acted  upon  by  an  alcoholic  solution  of 
bromine,  this  substance  is  absorbed  by  the  fatty  substance 
much  quicker  than  if  it  had  not  been  saponified.  This  ab- 
sorption is  assisted  by  a  more  complete  saponification,  and  it 
takes  place  with  a  production  of  heat  which  varies  for  every 
kind  of  oil. 

W^  shall  now  enter  into  some  details  in  regard  to  the  pro- 
cesses of  assaying  oils. 

Qualitative  Assays. 

Mi^st  Process. — It  consists  in  allowing  a  mixture  of  warm 
aqueous  sulphuric  acid  and  concentrated  nitric  acid  to  react 
on  oils  for  30  seconds.  The  quantity  of  acid  to  be  used 
varies  according  to  the  temperature  at  which  the  operation 
is  conducted. 

At  7°  C.  (44.6°  F.),  8°  C.  (46.4°  F.),  9°  C.  (48.2°  F.),  the 
quantities  to  be  taken  are — 


ADULTERATION  OF  THE  FATTY  BODIES. 


145 


1st.  Sulphuric  acid  sp.  gr.  1.80  to  1.84 

(650to  660  B.)        .       .       .  7  cub.  cent.  (1.89  flu.  dr.) 

2d.   Water   3      "        (0.81  flu.  dr  ) 

3d.  Oil   4      "        (1.08  flu.  dr.) 

4th.  Nitric  acid  sp.  gr.  1.35  to  140  (35© 

to40OB.)   3  " 

At  10°  C.  (50°  r.).  11°  C.  (51.8°  F.j,  12°  C.  (53.6°  F.),  13° 
C.  (55.4°  F.),  14°  C.  (57.2°  F.),  take 

1st.  Sulphuric  acid     ....  6  cub.  cent.  (1.62  flu.  dr.) 

2d.  Water   3 

3d.  Oil   4  " 

4th.  Nitric  acid   3  " 

At  15°  C.  (59°  F.),  16°  C.  (60.8°  F.),  17°  C.  (62.6°  F.),  18° 
C.  (64.4°  F.),  19°  C.  (66.2°  F.),  take 

1st.  Sulphuric  acid     .      .      .      .  5  cub.  cent.  (1.35  flu.  dr.) 

2d.  Water   3  " 

3d.  Oil   4  " 

4th.  Nitric  acid   3  " 

At  20°  C.  (68°  F.),  21°  C.  (69.8°  F.),  22°  C.  (71.6°  F.),  28° 
C.  (73.4°  F.),  24°  C.  (75.2°),  take 

1st.  Sulphuric  acid    ....  4  cub.  cent. 

2d.  Water   3  " 

3d.  Oil   4  " 

4th.  Nitric  acid   3      "        (0.81  flu.  dr.) 

Measure  in  a  graduated  tube  the  sulphuric  acid,  which  is 
introduced  into  a  test-tube  closed  at  one  end,  20  centimetres 
(7.9  inches)  in  height,  and  18  millimetres  (0.70  inch)  in 
diameter.  Let  the  acid  drain  well,  then,  in  the  same  tube, 
measure  the  water  which  is  poured  upon  the  acid,  and  mix 
quickly  by  shaking  the  tube.  The  produced  heat  ought  to 
range  from  44°  C.  (111.2°  F.)  to  48°  C.  (118.4°  F.).  Into  this 
warm  mixture  pour  the  oil  which  has  been  measured  in 
another  graduated  tube.  Lastly,  add  the  nitric  acid  care- 
fully measured.  Apply  a  sheet  of  India  rubber  to  the  open- 
ing of  the  tube  and  shake  it  strongly  for  30  seconds,  then 
dip  it  immediately  into  cold  water,  where  it  is  left  for  five 
minutes.  The  oil  collects  at  the  surface  of  the  liquid  and 
begins  to  be  colored.  After  five  minutes,  remove  the  tube 
10 


146 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


and  keep  it  in  a  vertical  position  where  it  is  left  to  rest. 
Fifteen  minutes  after  observe  the  coloration. 

When  the  acid  mixture  is  not  warm  enough,  the  earth-nut 
oil  blackens  very  little  or  not  at  all ;  if  the  tube  is  not  dipped 
into  cold  water,  the  brown  coloration  easily  disappears  and 
becomes  dark-red.  The  reaction  of  the  warm  acid  mixture 
on  the  coloring  matter  ought  to  be  suspended  by  an  immer- 
sion of  five  minutes  in  cold  water."^ 

The  following  Table  A  gives  the  colorations  taken  by  dif- 
ferent oils.  ^ 

Note. — It  is  important  that  the  sulphuric  acid  should  always  be 
very  concentrated  (sp.  gr.  1.80°  to  1.84°). 

^  The  temperature  which  succeeds  the  best  is  from  160  C.  (60.80  F.) 
to  170  C.  (62.60  F.),  in  using  5  cub.  cent,  of  sulphuric  acid. 


ADULTERATION  OF  THE  FATTY  BODIES. 


147 


Temperature. 
67.4°  ;  69.2° ;  71°  ;  72.8° ;  74.6°  F. 

Acid. 

Colorless,  or 
slightly 
greenish 

Yellow,  in- 
fusion of 
saffron 

Slightly  or- 
ange color, 
which  dis- 
appears 

Colorless 

Colorless 

Very  little 
coloration 

o 

straw 
Straw 

Orange 

Soot,  or  in- 
fusion of 
cott'ee 

Red-orange, 
or  red-cur- 
rant 

Red-currant 
Dark  brown 

o 

CD 
O 

to 

•  o 
9  ^. 
3  ^ 
tS  .~ 

1% 

B  CO 
<s   .  - 
H  0 

c* 

CO 

o 

03 

o 

Acid. 

Colorless,  or 
slightly 
greenish 

Yellow,  in- 
fusion of 
saffron 

Slightly  or- 
ange color, 
which  dis- 
appears 

Colorless 

Colorless 

Very  little 
coloration 

o 

Pale  straw 
Dark  straw 

Straw,  yel- 
lowish shade 
the  most  of- 
ten; dark 
straw 

Dark  orange 

Soot,  or  in- 
fusion of 
coffee 

Red-orange, 
or  red  cur- 
rant 

Red-currant 
Dark  brown 

p^* 

o 

<N 

®  ^ 

u  ' 
P.  ^ 

i  s 

e» 
•o 

o 

Acid. 

Colorless,  or 
slightly 
greenish 

Orange-red 

Very  little 
coloration 

Colorless 

Colorless 

Very  little 
coloration 

Oil. 

Pale  nankin 
Dark  nankin 

Nankin,  a 
little  yel- 
lowish 

Red-brown 

Soot,  or  in- 
fusion of 
coffee 

Red-orange, 
or  red-cur- 
rant 

Red-currant 
Dark  brown 

Temperature. 
44.6°  ;  46.4°  ;  48.2°  F. 

Acid. 

Colorless 
Greenish 

Strongly  color- 
ed orange 

Very  little  col- 
oration 

Very  little  col- 
oration 

Colorless 

Very  little  col- 
oration 

o 

Dark  nankin 
Dirty-yellow 

Dirty-yellow 

Red-brown 

Soot,  or  infu- 
sion of  coffee 

Brown.  In  one 
quarter  of  an 
hour  becomes 
red-orange. 
Red-currant 

Dark  brown 

Oils  Used. 

Virgin  olive  oil. 
Ordinary  "  " 

Rancid  " 

Sesame  oil, 
Earth-nut  oil, 

Colewort  oil,  not 
refined, 

Colewort  oil,  re- 
fined, 
Neat's  foot  oil. 

148  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Falsifications  of  Lard. 

Alterations. — Lard  exposed  to  the  air  in  jars  not  well  closed 
becomes  rancid  and  turns  yellow.  If  kept  in  copper  vessels, 
or  in  earthen  jars  glazed  with  sulphide  of  lead,  it  may,  by 
contact  with  the  air,  attack  the  copper  or  the  glazing,  and 
then  contain  stearate  and  oleate  of  copper  or  lead.  The  cop- 
per is  detected  by  pouring  on  the  grease  a  few  drops  of  am- 
monia, which  immediately  becomes  blue.  A  red  coloration 
is  given  by  a  solution  of  yellow  prussiate  of  potash. 

Lead  is  detected  by  burning  the  lard,  and  carefully  exam- 
ining the  residuum  to  see  if  there  are  any  metallic  globules. 
The  residuum  is  then  treated  by  nitric  acid  which  dissolves  the 
metal.  Filter,  and  to  the  filtrate  add  sulphuric  acid,  which 
gives  a  white  precipitate. 

Lard  may  also  contain  an  excess  of  water,  which  is  ascer- 
tained by  pressing  and  softening  it  with  a  wooden  spatula  ; 
the  water  oozes  from  it  in  the  form  of  drops.  By  melting 
it  at  a  low  temperature,  the  water  separates  from  the  grease. 

Falsifications. — The  principal  adulterations  of  lard  are  the 
addition  of  common  salt,  the  admixture  of  a  grease  of  infe- 
rior quality,  or  that  of  a  kind  of  grease  obtained  by  the 
cooking  of  pork  meat.    Plaster  of  Paris  is  sometimes  added. 

The  addition  of  salt  is  easily  detected  by  digesting  the 
lard  with  hot  distilled  water.  The  salt  in  the  water  is  abun- 
dantly precipitated  with  nitrate  of  silver.  The  precipitate  is 
white,  soluble  in  ammonia,  and  insoluble  in  nitric  acid;  it 
becomes  black  when  exposed  to  the  light. 

piaster  of  Paris  is  detected  by  melting  in  warm  water  the 
suspected  lard.  If  it  contains  plaster,  this  falls  to  the  bottom 
in  the  form  of  a  white  powder.  The  inferior  greases  are 
often  very  difficult  of  detection  ;  they  are  ascertained  by  the 
less  white  color  of  the  lard  and  by  a  taste  entirely  difterent. 
The  greases  from  the  cooking  of  pork  meat  give  to  the  lard 
a  grayish  color,  a  soft  consistency,  a  salted  and  disagreeable 
taste. 


ADULTERATION  OF  THE  FATTY  BODIES. 


149 


Falsifications  of  Tallows. 

Tallows  are  generally  adulterated  with  greases  of  inferior 
quality.  Water  is  also  incorporated  in  them  by  a  long  beat- 
ing. Cooked  and  mashed  potatoes  have  been  also  introduced 
into  them.  Fecula,  kaolin,  white  marble,  sulphate  of  baryta, 
are  also  added  to  tallows.  The  principal  adulteration  is  the 
addition  of  bone  tallow  ;  properly  speaking,  it  is  not  a  falsi- 
fication, it  is  only  a  change  in  the  quality  of  the  product. 

The  mineral  matters,  the  fecula,  the  cooked  potatoes,  are 
easily  ascertained  by  dissolving  the  tallow  in  ether  or  sul- 
phide of  carbon.  All  the  foreign  substances  remain  insolu- 
ble, and  their  nature  is  then  easily  determined. 

Iodine  water,  or  the  alcoholic  tincture  of  iodine,  will  color 
blue  the  insoluble  residuum,  if  it  contains  fecula.  This 
fecula  can  be  determined  in  the  tallow  by  triturating  the 
grease  with  iodine  water  and  adding  a  few  drops  of  sulphuric 
acid.  The  blue  color  will  appear  immediately  if  there  be 
fecula. 

For  the  mineral  substances  there  is  a  process  as  simple  as 
the  above  to  ascertain  their  presence  in  tallow  ;  it  is  to  melt 
the  tallow  with  twice  its  weight  of  water.  The  foreign  sub- 
stances are  precipitated  and  the  grease  floats  on  the  surface. 

Instead  of  using  ordinary  water,  the  tallow  may  also  be 
boiled  for  a  few  minutes  with  2  parts  of  acidulated  water  for 
one  part  of  tallow.  The  whole  is  allowed  to  rest  in  a  test 
glass,  or  in  a  funnel  placed  over  a  water-bath,  kept  at  a  tem- 
perature of  about  40°  C.  (104°  F.),  so  as  to  prevent  the  too 
rapid  cooling  of  the  tallow,  and  to  give  time  to  the  impuri. 
ties  to  separate  and  deposit.  Iodine  added  in  this  last  treat- 
ment will  disclose  the  presence  of  fecula  or  starch. 

To  ascertain  the  presence  of  water,  knead  dried  powdered 
sulphate  of  copper  with  the  tallow  (half  its  volume  of  the 
powder).  If  there  be  much  water,  the  mixture  will  take  a 
blue  color,  if  the  tallow  is  white ;  and  greenish,  if  the  grease 
is  yellowish.  As  for  the  quantity  of  water  added,  the  only 
way  to  ascertain  it  is  by  drying  a  sample  in  an  oven. 


150  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Falsifications  of  Waxes. 

The  yellow  and  white  beeswax  are  adulterated,  1st.  With 
earthy  substances^  flour  of  sulphur^  yellow  ochre ^  calcined  hones  ; 
2d.  With  resins^  pitch ;  3d.  With  amylaceous  substances,  flour ^ 
starch,  etc.,  sawdust  ;  4th.  With  fatty  substances,  tallow,  stearin, 
paraffine,  stearic  acid;  5th.  With  lualer.  Let  us  examine  in 
turn  these  different  adulterations. 

Yelloiv  Wax  and  Sulphur. — Projected  on  a  red-hot  piece  of 
iron,  such  a  wax  disengages  an  odor  of  sulphurous  acid. 

Yelloio  Wax  and  Yellow  Ochre. — This  falsification  is  ascer- 
tained by  melting  the  suspected  wax  in  warm  water.  There 
forms  at  the  bottom  of  the  vessel  a  yellow  precipitate,  which, 
dissolved  in  hydrochloric  acid,  gives  a  liquor  in  which  a  few 
drops  of  yellow  prussiate  of  potash  will  produce  a  precipitate 
of  Prussian  blue.  Instead  of  melting  the  wax  in  water,  it 
may  be  dissolved  in  spirits  of  turpentine,  ether,  or  benzine ; 
the  wax  alone  will  be  dissolved. 

Yellow  and  White  Wax  and  Calcined  Bones. — This  fraud  is 
also  ascertained  by  the  fusion  of  the  wax  in  warm  water,  or 
its  solution  in  spirits  of  turpentine,  ether,  etc.  The  sub- 
stance which  falls  to  the  bottom  of  the  vessel  in  the  first 
case,  or  the  insoluble  part  in  the  second,  is  treated  by  warm 
hydrochloric  acid.  The  acid  liquor  gives,  by  the  addition  of 
ammonia,  a  white  precipitate  of  phosphate  of  lime,  which, 
after  a  complete  washing,  becomes  yellow  by  the  addition  of 
a  drop  of  nitrate  of  silver. 

Wax  and  Resins,  Pitch,  etc. — The  presence  of  these  sub- 
stances in  wax  is  ascertained  by  the  following  characteris- 
tics : — 

1.  The  wax  sticks  to  the  teeth  when  chewed  ;  pure  wax 
does  not  stick.  The  taste  betrays  the  foreign  substance ;  the 
wax  is  viscous,  and  its  color  and  odor  are  different. 

2.  Treated  by  cold  alcohol,  this  reagent  dissolves  the  resin, 
the  wnx  being  but  slightly  soluble  or  nearly  insoluble.  The 
alcoholic  liquor  being  evaporated  gives  resin  for  a  residuum. 

3.  Treated  by  3  or  4  drops  of  sulphuric  acid,  it  gives,  by 
operating  on  the  liquefied  wax,  a  red  coloration  ;  the  wax  in 


ADULTERATION  OF  THE  FATTY  BODIES. 


151 


Bolidifying  takes  a  violet  shade.  This  reaction  is  very  pre- 
cise, and  enables  us  to  detect  1  per  cent,  of  resin  ;  however, 
in  this  last  case,  the  resin  has  a  greenish  shade. 

Wax  and  Starch  or  other  Amylaceous  Substances. — The  pres- 
ence of  starch  is  ascertained  by  Delpech's  process,  by  dissolv- 
ing the  wax  in  spirits  of  turpentine,  w^hich  does  not  dissolve 
the  starch  or  other  amylaceous  substances.  To  detect  starch, 
boil  the  wax  with  water,  and  test,  by  an  alcoholic  tincture 
of  iodine,  the  cold  and  clear  liquor.  A  blue  color  indicates 
the  presence  of  starch.  The  wax  may  also  be  treated  by 
warm  water  acidulated  with  2  per  cent,  of  sulphuric  acid. 
The  starch  is  transformed  into  dextrine  and  remains  in 
solution,  leaving  the  wax  to  cool  and  solidify.  By  weighing 
the  latter,  the  difference  in  weight  gives  the  proportion  of 
starch. 

Wax  adulterated  by  fecula  is  less  unctuous  and  less  tena- 
cious than  pure  wax;  by  striking  it,  it  divides  into  small 
fragments ;  its  color  is  a  tarnished  yellow.  It  does  not 
entirely  dissolve  in  spirits  of  turpentine,  and  leaves  a  white 
deposit  easily  detected  by  the  tincture  of  iodine. 

The  introduction  of  flour  into  wax  is  also  practised,  some 
samples  containing  as  much  as  68  per  cent.  A  w^ax  containing 
10  per  cent,  of  flour  takes  a  bluish  shade  by  standing  in 
iodine  water.  A  wax  adulterated  by  23  per  cent,  of  flour 
falls  to  the  bottom  of  the  water;  pure  wax  floats  on  the  sur- 
face of  this  liquid. 

Wax  and  Tallow, — Wax  adulterated  by  tallow  is  ascer. 
tained,  first  by  the  taste  and  disagreeable  odor ;  it  is  less 
brittle,  and  more  unctuous  to  the  touch. 

Thrown  on  red-hot  coals,  this  wax  disengages  a  disagree- 
able odor,  and  gives  a  thicker  smoke  than  pure  wax. 

The  variations  in  the  melting  point  enable  us  to  ascertain 
the  adulteration.  This  process  is  precise  enough,  since  it 
enables  us  to  detect  one-eighth  of  tallow  in  the  wax. 


152  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


SECTION  VI. 

THE  CHEMICAL  EQUIVALENTS  APPLICABLE  TO  SOAP. 

By  equivalents  the  chemist  understands — to  maintain  the 
simplest  example — the  certain  equal  values  of  the  different 
acids,  which  are  requisite  to  produce  with  a  certain  amount 
of  weight  of  a  base  a  solid  chemical  combination  ;  just  in  the 
same  manner  as  if  we  chose  a  certain  acid  for  a  departure. 
In  the  first  case,  we  would,  for  instance,  require  for  47.11 
parts  in  weight  of  potash,  40  parts  weight  of  sulphuric  acid, 
54  parts  weight  of  nitric  acid,  36.4  parts  weight  of  muriatic 
acid,  75.0  parts  weight  of  tartaric  acid,  51  parts  weight  of 
acetic  acid,  etc.,  all  these  acids  supposed  to  be  free  from  water, 
in  order  to  produce  the  corresponding  neutral  salts  of  these 
acids  with  potash.  The  acids  are  therefore  according  to  the 
stated  parts  weight  equivalent.  To  neutralize  40  parts  in 
weight  of  sulphuric  acid  47.11  parts  weight  of  potash,  31.0 
parts  weight  of  soda,  17  parts  weight  of  ammonia,  28  parts 
weight  of  lime,  76.5  parts  weight  of  barytes,  etc.,  would  be 
requisite.  Here  the  bases  are  according  to  the  stated  weight 
amounts  equivalent.  In  what  manner  these  calculations 
have  been  ascertained  does  not  pertain  to  this  treatise. 

Entirel}^  in  the  same  manner  correspond  the  various  seba- 
cic  acids,  which  are  applied  in  the  making  of  soap,  respecting 
their  combinations  with  the  oxide  of  glyceryl,  that  is,  the 
fats  themselves ;  and  it  would  according  to  our  conviction 
be  a  very  great  progress  in  the  production  of  soap,  if  here 
too,  as  is  done  in  the  making  of  salts  from  one  acid  and  one 
base,  for  the  fixed  amount  of  sebacic  acid,  the  fixed  amount 
of  alkali  would  be  applied.  Many  will  probably  shrug  their 
shoulders  in  a  contemptuous  manner,  when  reading  this  pro- 
position, and  state,  that  the  correct  proportions  could  be 
easier  gained  by  experiment.    But  the  author  has  been  wit- 


CHEMICAL  EQUIVALENTS  APPLICABLE  TO  SOAP.  153 

ness  to  the  fact  as  to  what  this  experimenting  means.  If  for 
instance  a  want  of  alkali  is  ascertained,  we  add  at  random 
— since  every  support  for  a  correct  determination  is  wanting 
— a  portion  of  lye.  By  the  next  test  we  find  that  the  soap 
has  too  much  "  bite,"  i.  e.,  an  overplus  of  alkali,  which  is  like- 
wise to  be  abated  at  random,  by  adding  more  fat.  Thus  it 
changes  alternately  to  and  fro,  till  at  last  the  true  proportion 
is  deemed  to  have  been  found.  Thus  comes  the  trouble  that 
we  finally  do  not  know  what  yield  of  soap  may  be  calculated 
upon,  for  as  a  rule  the  fat  which  is  added  for  correction  is 
never  weighed  into  the  kettle,  and  thus  all  control  of  the 
work  ceases.  By  using  the  equivalents  all  uncertainty 
vanishes  at  once,  and  the  corresponding  necessary  amounts 
of  fat  and  alkali  can  be  ascertained  with  the  same  security 
in  advance,  as  if  the  point  in  question  had  been  to  neutralize 
a  certain  quantity  of  alkali  by  sulphuric  or  nitric  acid.  The 
other  is  even  easier,  since  a  little  overplus  of  alkali  in 
the  case  of  soap  does  not  matter,  and  by  natron  soap  is  re- 
moved by  the  cutting  of  the  pan  with  salt,  but  in  case  of 
soft  soaps  it  becomes  very  necessary.  The  advice  which  we 
here  desire  to  impart  to  soap  manufacturers  is  not  merely 
founded  upon  tests  made  on  a  small  scale,  but  upon  experi- 
ence gained  by  experiments  in  the  working  up  of  fats  into 
soaps  on  an  extended  scale.  It  is  the  result  of  an  experience 
which  is  frequently  made  in  every-day  life,  that  even  errors 
are  upheld  with  the  greatest  stubbornness  by  those  who  can- 
not be  compelled  to  learn  anything  new.  In  our  case  it  is 
for  most  of  those  concerned  the  difficulty  of  determining  the 
strength  of  the  lyes.  And  yet  nothing  is  easier  than  this 
operation ;  but  even  if  it  were  more  difficult  and  required 
more  time,  these  would  hardly  enter  into  consideration  in 
comparison  with  the  loss  of  time  and  other  disturbances 
which  are  connected  with  the  correction  of  erroneous  pro- 
portions between  fat  and  alkali. 

The  equivalents  of  fats  which  are  used  in  making  soap  are 
among  themselves  not  so  different  that  in  practice  much 
consideration  need  be  shown  regarding  this,  although  it  may 
be  somew^hat  different  with  the  soaps  which  are  manufac- 


154  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


tured  from  the  same.  The  differences  are  in  fact  so  insig- 
nificant, that,  besides  a  small  loss  in  alkali,  it  would  not 
cause  the  least  disadvantage,  if  for  that  fat,  which  for  its 
saponification  requires  the  least  amount,  just  as  much  alkali 
were  taken,  as  if  we  had  to  do  with  a  fat,  which  for  its 
saponification  required  the  greatest  amount  of  alkali.  What 
alone  is  to  be  the  matter  of  consideration  in  this  case  is, 
from  the  outstart,  the  requisite  quantity  of  alkali,  but  on 
no  account  a  surplus,  or,  in  other  words,  it  is  to  be  ascer- 
tained in  advance,  how  much  fat  of  a  given  weight,  to  the 
lyes  on  hand,  has  to  be  taken  to  obtain  the  most  possible  neu- 
tral soap,  so  that  every  correction,  be  it  of  fat  or  be  it  of 
alkali,  becomes  superfluous. 

The  neutral  soaps  contain  for  1  equivalent  of  sebacic  acid 
1  equivalent  of  caustic  potash,  and  according  to  this  propor- 
tion the  quantity  of  alkali  must  likewise  be  measured  when, 
in  place  of  sebacic  acid,  the  neutral  fats  are  to  be  saponified. 

Inasmuch  as  we  now  know  the  composition  of  the  neutral 
fats — they  are  almost  without  exception  combinations  of  3 
equivalents  sebacic  acid  with  1  equivalent  of  glycerine,  the 
former  composed  one-half  of  oleic  acid — so  their  equivalents 
too  may  be  easily  calculated,  and  we  find  thus  the  threefold 
equivalent 


For  Tallow :  Tristearin   .  . 

^114 

Triolein   .  .  . 

H,o4 

o„ 

2 

For  Palm  Oil:  Tripalmitin 

Triolein  .  . 

^114 

H,o4 

o„ 

^216 

TT 

-*^202 

2 

For  Cocoa-nut  oil:  Trilaurin 

C.S 

H„ 

0.. 

Trimyristin 

He, 

Triolein  .  . 

^114 

Him 

P 

^282 

H264 

3 

0„  =  887 


H.„,  0,,  =  845 


H„  0,,  =  748 

For  Oleic  Acid  C,„  H,„  0,^=  884 


CHEMICAL  EQUIVALENTS  APPLICABLE  TO  SOAP.  155 

Since  these  figures  represent  the  threefold  equivalents  of 
the  respective  oils,  we  hence  need  for  their  saponification  3 
equivalents  of  alkali ;  of  natron  93  parts  in  weight,  and  of 
potash  104.76.  For  the  equivalent  weights,  for  instance  100 
kilogrammes  (220  lbs.),  of  those  fats  and  of  oleic  acid,  we 
would  therefore  require — 

For  Tallow  :      10.50  kg.  (23.1   lbs.)  soda  or  15.87  kg.  (34.91  lbs.)  potash 
Palm  Oil:   11.00  "   (24.3    "  )    "       16.66  "   (36.65  "  )  " 
"   Cocoa  Oil:  12.44  "   (27.37  "  )    "        18.82  "   (41.40  "  )  " 
Oleic  Acid:  10.52  "   (23.14  "  )    "        15.92  "   (35.02  "  )  " 

Whereas  a  small  overplus  of  alkali  is  not  only  not  harmful, 
but  really  enhances  the  saponification  of  the  fats,  we  may 
without  any  hesitation  to  100  parts  of  neutral  fat  take  12.0 
or  12.5  parts  soda,  and  for  soft  soaps  16  or  17  parts  of  potash, 
of  which  it  is  always  demanded  that  they  "bite"  strongly. 
An  addition  is  allowed  of  2  or  3  of  fluid  as  an  overplus;  if  the 
soap  contain  cocoa-nut  oil,  proportionately  more. 

From  the  above  it  evidently  follows  that  a  fat  furnishes 
the  more  soap,  without  regard  to  the  changing  contents  of 
water,  the  more  alkali  the  respective  sebacic  acids  demand 
for  their  saturation  or  saponification.  The  most  productive 
according  to  this  is  cocoa-nut  oil;  the  least  soap  furnished 
is  by  tallow. 


156  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


SECTIOIS'  VII. 

SAPONIFICATION— THEORETICAL,  CHEMICAL,  AND 
PEACTICAL. 

Soap,  in  common  parlance,  means  that  in  common  use  for 
various  purposes,  and  is  a  chemical  compound  resulting  from 
certain  constituents  derived  from  fats,  oils,  and  greases  of 
various  kinds,  both  animal  and  vegetable,  with  certain  sali- 
fiable bases,  which,  in  the  kind  of  which  we  write  and  called 
detersive  soaps,  are  potash  and  soda. 

Chemists  apply  the  name  of  soap  to  any  compound  of  the 
fatty  acids  with  a  base :  thus  we  have  lead  soap,  used  in 
pharmacy,  and  called  diachylon  plaster.  Zinc  soap  is  also 
used  in  medicine  and  in  painting.  Lime,  magnesia,  tin,  cop- 
per, mercury,  silver,  and  gold  are  made  into  soaps  that  find 
various  uses  in  the  arts.  Of  all  these  we  have  but  little  to 
write  except  of  lime  soap,  which  has  great  importance  in  the 
fabrication  of  stearic  acid  for  candles.  These  processes  will, 
however,  be  treated  of  in  our  section  on  candles. 

Caesium  and  rubidium  (oxides  of)  may  also  be  used  in 
forming  soaps  having  the  properties  of  a  potash  soap;  but, 
as  these  two  alkalies  have  thus  far  been  found  in  nature  in 
but  limited  quantities,  they  cannot  have  any  application  to 
our  art. 

Before  Chevreul  made  known  his  researches,  it  was  sup- 
posed that  fats  and  oils  formed  a  combination  with  alkalies. 
He,  however,  explained  that  fats,  w^hen  saponified  and  again 
separated,  had  properties  quite  different  from  those  existing 
before  saponification,  and  showed  that  fats  and  oils  are  com- 
pounds of  peculiar  acids,  stearic,  palmitic,  oleic,  etc.,  non- 
volatile substances,  while  fats  which  have  a  peculiar  odor 
have  in  addition  to  these  acids  volatile  fatty  acids,  as  butyric. 


SAPONIFICATION. 


157 


valerianic,  etc.,  and  they  were  all  combined  with  a  sweet 
principle  known  as  glycerine. 

Berthelot  held  and  proved  that  all  the  fats  and  oils  used- 
in  the  fabrication  of  soap  are  ethers  of  glycerine  CallgOg,  that 

substance  being  viewed  as  a  trivalent  alcohol   ^jj^  j"  ^s-  P^^- 

mitin,  for  instance,  the  principal  constituent  of  palm  oil,  is 
glyceryl  tripalmitate,  that  is,  glycerine  in  which  three  atoms 
of  hydrogen  are  replaced  by  the  radical  of  palmitic  acid 

3C^  H  0  [         Stearine  (tristearine)  and  oleine  (trioleine) 

have  an  analogous  constitution.  When  the  fats,  palm  oil  for 
instance,  are  saponified  with  caustic  alkalies,  say  caustic  soda, 
the  fat,  that  is  the  ether,  is  decomposed  into  alcohol,  i.  e. 
glycerine,  and  the  palmitate  of  sodium,  i.  e,  the  soap,  is 
formed,  according  to  the  following  equation : — 

Tripalmitin  |  gQ^^g  0  |  caustic  soda  SITaOH  = 

glycerine         j-  O3  and  sodium  palmitate  3  |  -^^^        j-  0. 

The  glycerine  formed  in  the  process  of  saponification  re- 
mains after  the  separation  of  the  soap  dissolved  in  the  mother 
liquor,  and  can  be  separated  and  utilized. 

Besides  the  mode  of  saponification  of  fats  and  oils  by  means 
of  the  metallic  bases,  i.  e.  alkalies,  there  are  several  other 
modes,  as  by  acids,  by  heat,  by  steam,  and  by  fermentation, 
which  will  be  explained  in  their  appropriate  place. 

Thus,  though  we  find  that  the  fats  and  oils  consist  of  so 
many  difterent  and  distinct  substances,  they  are  chiefly  dis- 
tinguished by  consistency  at  ordinary  temperatures,  the  liquid 
part  being  called  olein  and  the  solid  stearine,  and  their  con- 
sistency depending  upon  the  preponderance  of  one  or  the 
other  of  these  constituents.  Correctly  speaking,  stearine  the 
solid  part  may  not  be  all  stearine,  but  may  contain  margarin, 
palmitin,  etc.,  while  the  oleine  may  contain  margarin,  cocin, 
etc.  Yet  when  any  of  the  fatty  acids  are  separated  their 
action  with  the  alkalies  is  the  same,  and  they  can  be  united 
in  the  same  manner  to  form  soaps,  but  the  soaps  formed 


158  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


will  owe  their  greater  or  less  solidity  to  the  amount  of  the 
solid  or  liquid  constituents  of  the  fatty  body  or  sebacic  acid. 
In  the  saponification  of  the  fats  with  hydrate  of  lime  for 
the  purpose  of  forming  stearic  acid  for  candles  and  sepa- 
rating the  oleic  acid  and  liberating  the  glycerine,  either  of 
the  acids  is  the  more  readily  saponifiable,  and  for  the  oleic 
acid  the  lye  need  not  be  entirely  caustic,  as  it  can  be  saponi- 
fied with  carbonated  lyes. 

In  this  process  glycerine,  which  we  have  explained  is  a 
kind  of  alcohol,  takes  up  the  elements  of  water  with  which 
it  had  previously  been  formed  with  the  fatty  acids.  Gly- 
cerine forms  about  8  to  10  per  cent,  of  the  neutral  fats,  lard 
being  usually  richer  in  this  valuable  article. 

It  must  not  be  supposed  that  in  the  production  of  soap  the 
materials  combine  as  readily  or  as  rapidly  or  with  the  same 
exactness  as  ordinary  salts  form  to  make  a  union  or  a  decom- 
position, for  it  is  not  a  momentary  process.  On  the  contrary, 
it  occupies  a  considerable  length  of  time,  and  the  formation 
of  the  soap  is  not  complete  until  in  the  boiling  process  the 
fat  is  first  made  into  a  milky  emulsion  with  the  weaker  lye, 
and, by  the  further  addition  of  alkali,  it  becomes  saturated,  and 
finally  finished  and  separated  from  the  mother-lye,  and  is  ready 
for  use.  Or,  again,  when  the  soap  is  made  by  the  extempore 
or  cold  process,  it  is  at  first  combined  mechanically  ;  it  has  to 
remain  in  the  frames  for  some  hours  that  the  materials  may 
react  spontaneously  upon  one  another,  and,  by  increased  heat 
of  the  chemical  action,  saponification  is  completed.  So  we 
find  that  saponification  does  not  take  place  suddenly  and 
throughout,  but  passes  through  several  stages,  and  only 
gradually  are  the  sebacic  acids  decomposed  and  formed  into 
salts,  or,  in  other  words,  soaps. 

When,  however,  we  melt  tallow  with  as  little  heat  as  pos- 
sible, say  about  87.7°  C.  (100°  F.),  and  add  half  its  weight  of 
strong  alkali  of  36°  B.  of  the  same  temperature, and  constantly 
stir  for  some  time,  we  will  find  it  suddenly  acquire  a  solid 
consistency,  with  a  great  elevation  of  temperature,  proving 
the  great  chemical  attraction  of  the  materials.  Yet  saponi- 
fication is  not  yet  complete,  for  it  seems  to  have  an  excess  of 


SAPONIFICATION. 


159 


alkali,  which  it  does  not  lose  until  some  hours,  when  the  com- 
bination is  complete  and  the  soap  neutral. 

Despite  the  fact  that  saponification  is  increased  by  boiling, 
rapid  boiling  is  not  advantageous,  especially  in  the  prelimi- 
nary stages,  when  with  the  first  weak  lyes  the  emulsion  is 
forming.  A  moderate  heat  causes  a  better  combination,  and 
the  heat  should  not  be  much  increased  until  toward  the  end, 
when  the  mass  has  acquired  more  consistency  and  has  ab- 
sorbed sufiicient  alkali,  when  it  can  be  boiled  rapidly  to  a 
finish. 

When  the  alkali  is  dissolved  in  alcohol  and  mixed  with 
the  heated  or  melted  fats  or  oils,  the  combination  is  very 
rapid,  and  the  resulting  soap  contains  all  the  glycerine  which 
cannot  be  separated  except  by  a  decomposition  with  an  acid 
and  the  addition  of  some  water.  By  this  effect  the  obser- 
vant soap-maker  is  enabled  to  make  some  beautiful  soaps  of 
transparent  appearance,  which  will  be  more  fully  explained 
in  their  proper  place. 

Although  the  decomposition  of  the  sebacic  acid  with  caustic 
alkalies  will  take  place  at  common  temperatures,  yet  it  is  but 
slowly ;  but,  as  in  the  case  of  almost  all  chemical  processes, 
it  is  essentially  assisted  by  the  aid  of  heat.  If  the  melted 
fats  or  oils  are  mixed  with  the  lye  and  left  to  rest,  the 
greater  density  of  the  lye  will  cause  it  to  fall  to  the  bot- 
tom, while  the  fat  will  float  upon  the  top,  so  that  but  a 
limited  contact  will  be  possible  with  the  materials.  Thus, 
it  is  necessary  to  cause  a  constant  motion  of  all  the  particles 
by  stirring  or  by  boiling,  that  they  may  be  brought  together 
and  the  soap  in  forming  take  up  gradually  the  lye,  which  is 
being  absorbed  and  is  getting  weaker,  finally  becoming  clear 
when  the  decomposition  is  complete,  forming  a  neutral  salt, 
i.  e.,  soap  and  a  glycerine  oxide,  ^.  e.,  glycerine  and  water. 

If  it  were  possible  at  all  times  to  keep  perfectly  pure  ma- 
terials, fats  and  alkalies,  particularly  the  latter,  the  process 
of  soap-making  would  be  very  much  simplified,  and,  when 
combined  in  the  proper  proportions,  soap  would  be  formed 
and  the  quality  would  always  be  uniform.  But,  as  this  is 
impossible,  the  closest  attention  must  be  paid  to  the  action 


160  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

of  the  materials  in  hand,  in  order  to  learn  from  their  action 
what  it  is  necessary  to  use  and  what  it  is  proper  to  do  to  form 
a  pure  soap.  We  will  find  that  nearly  every  fat  or  oil  has  a 
somewhat  different  action  in  contact  with  the  lye,  though 
many  will  impart  their  peculiarities  to  the  other.  Thus  tallow 
will  impart  to  resin  its  mode  of  saponification,  without  which 
resin,  though  readily  saponifiable  in  lyes,  even  in  carbonated 
lyes,  will  not  make  a  detergent  or  solid  soap.  So  cocoa-nut 
oil  will  not  saponify  in  weak  lyes,  but  does  so  readily  in 
strong  lyes;  and,  when  mixed  in  certain  proportions  with 
other  fats,  it  can  be  boiled  in  weak  lyes,  and  will  impart  its 
property  of  saponifying  in  strong  lyes  when  in  other  pro- 
portions it  is  mixed  with  other  fats  and  oils.  Thus  we  see 
that  the  making  of  soap,  though  a  simple  matter,  yet  re- 
quires a  close  attention  to  these  pectiliarities  to  acquire  the 
requisite  skill. 

We  thus  find,  in  making  soap  by  boiling  the  fatty  bodies, 
that,  though  they  may  contain  many  impurities,  and  the 
alkalies  or  bases  may  have  a  larger  percentage  of  foreign 
salts  and  other  extraneous  substances,  yet  by  this  mode  of 
manipulation,  of  first  forming  an  emulsion  with  a  portion  of 
the  lye  and  boiling  to  a  clear  liquid,  and  in  the  second  lyes 
using  a  portion  of  culinary  salt  (chloride  of  sodium),  or  what 
is  called  "  cutting  the  pan,"  the  soap  that  has  formed  will 
separate,  and,  with  all  the  unsaponified  fat,  float  on  the  sur- 
face, and  the  salt  and  most  of  the  impurities  will  fall  to  the 
bottom  with  the  mother-liquor  or  spent  lye,  which  can  be 
removed,  and  the  soap,  if  finished,  put  in  the  frames,  or,  if 
not  sufficiently  purified,  it  can  be  again  boiled  with  weaker 
lye  and  salt,  again  cut  and  separated,  or  it  can  be  fitted  or 
finished  in  weaker  lye  to  give  it  the  proper  consistency,  or 
boiled  in  strong  lye,  which  also  separates  and  can  be  removed, 
as  the  case  may  require.  Culinary  salt  is  here  very  useful, 
but  it  should  be  in  rather  strong  solution,  otherwise  a  portion 
will  remain  in  the  soap  dissolved  in  the  water.  The  proper 
concentration  of  the  salt  solution  is  known  by  the  manner 
in  which  the  soap  appears  on  the  stirrer,  the  soap  separating 
in  curds  from  the  liquid.    The  liquid  in  the  pan  separates 


SAPONIFICATION. 


161 


and  falls  to  the  bottom,  while  the  soap  is  floating  on  the 
top,  forming  into  slabs,  and  then  into  grains  or  curds,  when 
the  heat  is  removed,  allowed  to  rest,  that  the  spent  lye  may 
subside  and  be  run  off,  or  the  soap  may  be  ladled  out  into 
frames ;  and  the  soap  is  made. 

Soap  as  here  noticed  is  also  insoluble  in  strong  lyes,  and 
when  it  has  taken  up  all  that  it  can,  or  becomes  from  long 
boiling  saturated,  it  floats  upon  the  surface  of  the  lye,  though 
it  is  possible  to  add  water  or  weak  lye  and  it  is  often  filled 
or  sophisticated  in  this  manner. 

Other  salts  have  the  property  of  separating  soap  from  its 
lyes,  as  chloride  of  potassium,  acetate  of  potassium,  chloride 
of  ammonium,  or  sal  ammoniac  and  sulphate  of  soda,  the 
latter  salt,  however,  is  sometimes  added  to  soap  made  from 
weak  stock,  bone,  or  kitchen  fat,  etc.,  having  the  property 
of  hardening  it  and  making  it  more  marketable,  but  it  must 
be  in  limited  quantities  in  strong  solution  and  after  the  soap 
is  framed,  and  stirred  in  mechanically,  that  it  may  not  de- 
compose the  soap.  Carbonate  of  soda  has  also  this  hardening 
property,  and  like  the  sulphate  it  must  be  added  in  strong 
solution  and  crutched  into  the  finished  soap. 

From  what  we  have  already  said,  it  will  be  gleaned  by  the 
intelligent  reader  that  the  saponification  of  the  ordinary 
fatty  bodies  with  the  usual  alkalies  and  the  formation  of 
marketable  soaps  is  not  a  complicated  matter  but  a  simple 
process,  demanding,  however,  much  care  and  exactness, 
and  resolves  itself  into  the  neutralization  of  the  fatty 
acids  with  the  caustic  alkalies.  Thus  we  will  analyze  a 
stearine  soap:  stearate  of  soda,  Ci,^HjjoO,2+ 3(NaO.HO),= 
^(i^^aO.CsgH^sOg)  or  stearic  acid  soda,  and  CgHgO^  or  glycerine. 


Similar  equations  apply  to  almost  all  other  combinations  of 
the  fatty  acids  with  the  bases. 

Soaps  made  with  potash  lye  are  always  soft  and  retain 
their  glycerine,  and,  owing  to  the  hygroscopic  character  of 


f  825  parts  stearic  acid 


890  parts  stearine]    %        ^t;':,,,;,,,-,^  ) 


L   27    "    water  ^ 


give  93  parts  glycerine 


11 


162 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


the  base,  they  are  constantly  absorbing  water  from  the  at- 
mosphere and  becoming  softer,  100  parts  of  potash  soap  having 
been  known  to  absorb  25  parts  of  water  in  a  few  weeks. 
These  soaps  are  very  rarely  neutral  but  almost  always  con- 
tain free  alkali,  caustic  or  carbonated  lye.  Yet  they  are  an 
important  article  of  commerce,  having  various  uses  in  the 
arts,  and  are  in  many  countries  used  for  domestic  purposes, 
particularly  in  countries  where  wood  is  abundant  and  is  used 
as  fuel  and  wood  ashes  are  plenty. 

The  making  of  hard  soap  from  potash  lye  is  done  by  first 
saponifying  with  wood-ash  or  potash  lye  and  then  cutting 
the  soap  with  culinary  salt,  forming  a  double  decomposition, 
the  chlorine  of  the  salt  uniting  with  the  potash  forming 
chlorate  of  potash,  the  soda  uniting  with  the  fatty  acid  and 
forming  a  hard  soap.  While  it  is  impossible  to  extract  all  the 
potash  by  this  means,  it  is,  however,  no  disadvantage,  but 
tends  to  improve  the  quality  by  keeping  the  soap  plastic. 
In  this  decomposition  the  soap  also  loses  all  its  glycerine, 
it  being  carried  down  with  the  sub-lye. 

The  neutral  fats  may  also  be  decomposed  by  means  of 
super-heated  steam  at  260°  to  330°  C.  (500°  to  626°  F.). 
Tilghman  has  invented  an  apparatus  for  this  purpose,  for  the 
production  of  glycerine  on  an  extensive  scale.  The  glycerine 
at  this  temperature  separates,  and  the  sebacic  acids  resulting 
are  readily  saponified  in  carbonated  alkali.  This  process  is 
conducted  on  an  improved  method  by  Milly,  with  the 
addition  of  a  little  hydrate  of  lime  (milk  of  lime)  in  connec- 
tion with  a  pressure  of  steam  at  7  to  8  atmospheres,  170°  C. 
(338°  F.).  The  resulting  lime  soap,  the  fatty  acids,  and  the 
glycerine  could  be  easily  separated. 

By  using  one-half  of  one  per  cent,  of  caustic  alkali  at  the 
above-mentioned  pressure  and  heating,  the  glj'cerine  will  be 
separated  in  about  10  hours  and  can  be  drawn  from  the 
bottom  of  the  covered  boiler,  while  the  remaining  sebacic 
acids  can  be  formed  into  soap  in  the  usual  manner. 

Or  this  process  can  be  conducted  by  means  of  a  still  and 
worm,  distilling  off  the  sebacic  acids  and  afterwards  extract- 
ing the  glycerine  from  the  residuum.    In  either  case  the 


SAPONIFICATION. 


163 


sebacic  acids  can  be  easily  saponified,  having  a  greater  affinity 
for  the  alkalies  when  they  have  parted  with  their  glycerine. 

Glycerine  now  of  great  value  for  such  varied  purposes  is 
made  in  one  or  other  of  the  above  described  processes,  but  gen- 
erally by  means  of  super-heated  steam  acting  upon  beef  or 
mutton  tallow  or  hog's  lard,  in  the  process  of  making  stearic 
acid  for  candles,  to  which  all  of  these  processes  are  applicable. 
This  process  has  in  view  the  production  of  those  useful  sub- 
stances, stearic  acid  for  candles,  oleic  acid  for  soaps,  and 
glycerine  for  the  arts  and  for  pharmacy.  The  different 
changes  may  be  explained  thus: — 

Below  is  a  more  simple  equation,  and  one  that  will  explain 
quite  as  well  the  usual  changes  that  take  place  when  two 
soap  materials  are  brought  into  contact  to  form  a  soap ;  for 
instance,  if  we  take  neutral  stearine  with  hydrate  of  soda,  the 
reaction  may  be  stated  thus: — 

Stearine. 

^  A  !  ^ 

stearate  of  oxide  of  glyceryl  +  soda  -f  water  = 
Btearate  of  soda  -f  hydrate  of  the  oxide  of  glyceryl 

*  Y  '   V  ' 

Hard  soap.  Glycerine. 

Of  course  the  same  simple  equation  can  be  applied  to  oleine, 
substituting  it  for  stearine. 

We  have  remarked  that  the  consistency  of  a  soap  is  affected 
by  the  melting-point  of  the  fats  used,  and  is  more  or  less 
hard  accordingly,  and  it  may  frequently  occur  that  the 
manufacturer  will  have  many  soap  greases  such  as  bone  fat, 
glue  fat,  kitchen  grease,  etc.,  and  some  that  are  recovered 
from  offal  and  wool  washing,  etc.  These  greases  are  techni- 
cally called  "weak  stock,"  and  produce  when  used  alone,  and 
particularly  with  rosin,  too  soft  a  soap,  that  melts  and  wastes 
in  the  water  in  using.  These  soaps  can  be  improved  by  an 
artificial  hardening  by  adding  5  per  cent,  of  crystals  of  sul- 
phate of  soda  dissolved  in  the  least  possible  amount  of  water, 
or  the  addition  of  10  to  15  per  cent,  of  the  solution  of  silicate 


164 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


of  soda  at  50°  B.  will  have  a  like  beneficial  eftect.  This 
filling  is  added  by  crutching  it  into  the  yet  warm  finished 
soap. 

Gossage  was  about  the  first  person  to  propose  the  use  of 
soluble  glass  as  a  useful  addition  to  soap,  and  as  we  have  seen 
above  with  good  effect,  but  it  is  sometimes  used  in  excess  to 
adulterate  and  cheapen  genuine  and  good  soaps.  It  has, 
however,  a  detersive  power,  the  free  alkali  it  contains  being 
a  solvent  of  grease  and  dirt.  Silicated  soaps  are  much  in 
vogue,  and  will  be  fully  described  in  their  proper  place,  w^hen 
also  other  fillings  for  soap  perhaps  not  so  suitable  will  be 
mentioned. 

We  have  already  given  some  of  the  characteristics  of  rosin 
or  colophony,  a  substance  much  used  in  domestic  soaps.  It 
consists  of  the  acids,  pinic,  sylvic,  and  colophonic,  in  differ- 
ent proportions,  each  having  an  equal  afiinity  for  alkalies. 
To  some  kinds  of  soap  it  gives  a  useful  property,  causing 
a  softer  consistency,  to  tallow  soap  for  instance,  and  so  may 
be  considered  in  the  light  of  an  ameliorator.  Though  readily 
saponifiable,  it  does  not  alone  make  a  useful  soap,  and  when 
added  to  other  soaps  it  must  not  be  in  greater  proportion 
than  fifty  per  cent,  of  the  fat  used,  or  it  will  affect  its  quality. 
The  best  results  are  obtained  when  it  is  saponified  alone, 
and  added  to  the  other  finished  soap,  while  still  hot,  and 
thoroughly  crutched  in. 

Soap  is  not  entirely  soluble  in  cold  water.  When  used,  the 
alkali  is  united  with  the  grease  and  dirt,  and  the  fatty  acids 
are  set  free  and  float  away,  and  may  afterwards  be  recovered. 
In  hot  water  soap  will  dissolve  and  form  an  opaque  solution, 
but  the  separation  occurs  when  it  cools,  the  solution  becom- 
ing clearer,  while  the  fatty  acids  float  upon  the  surface.  These 
fatty  acids  when  recovered  can  be  purified  and  again  used  to 
form  other  soaps.  Alcohol  dissolves  pure  soap  in  all  propor- 
tions, and  on  cooling  forms  a  clear  jelly.  This  property  is 
utilized  to  make  various  transparent  soaps. 

Some  writers  in  our  art  advise  the  forming  of  the  neutral 
fats  into  sebacic  acids,  and  then  saponifying  with  carbonated 
alkalies,  but  unless  the  saving  of  the  glycerine  is  an  object 


SAPONIFICATION. 


165 


there  is  little  economy  in  the  method,  for  the  saponification 
with  carbonated  lyes  is  a  tedious  process,  and  the  escaping 
carbonic  acid  causes  a  great  deal  of  foam,  and  it  takes  much 
more  time  than  boiling  with  the  usual  caustic  lyes.  More- 
over, the  soap  so  made  is  never  as  good,  as  it  always  retains 
a  spongy  condition,  and  dissolves  too  easily  in  water. 

So  it  will  be  unnecessary  to  say  that  all  these  processes  or 
methods,  having  in  view  the  avoidance  of  caustic  alkalies 
in  manufacturing  soap,  have  signally  failed ;  as  the  making 
of  soap  is  founded  upon  true  chemical  principles,  and  on 
well-established  rules,  so  that  it  is  hazardous  for  any  one  to 
deviate  from  methods  founded  upon  such  long  and  well  tried 
experience. 

Yet  let  it  not  be  supposed  that  there  is  nothing  more  to 
learn.  On  the  contrary,  the  experiments  of  experts  are  con 
stantly  throwing  new  light  upon  the  art,  which  with  the  in- 
vention of  new  appliances  has,  in  a  remarkable  degree,  im- 
proved the  quality  of  nearly  all  soaps  in  use.  But  what  is  al- 
ready known  is  founded  upon  sound  principles,  and  it  would 
be  a  loss  of  time  and  money  for  a  novice  to  experiment  in  the 
direction  already  covered  by  those  long  accustomed  to  the 
subject,  and  when  experience  founded  on  science  may  be 
taken  as  the  best  guide. 

Yet  as  we  recognize  that  the  art  of  the  fabrication  of  soap 
is  a  progressive  one,  and  new  and  untried  materials  are  con- 
stantly being  discovered  that  might  find  useful  or  economical 
application  in  it,  so  the  enterprising  manufacturer  will  al- 
ways be  on  the  alert,  to  endeavor  by  new  means  or  new 
materials  to  improve  his  processes,  or  produce  new  goods. 


166 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


SECTION  VIII. 

ALKALIMETRY. 

The  proper  knowledge  of  the  constituents  of  the  alkalies 
used,  with  their  preparation  for  the  decomposition  of  the 
neutral  fats  or  the  sebacic  acids,  is  beyond  all  doubt  the  most 
important  in  the  art  of  making  soap;  and  the  difficulties 
attending  the  attainment  of  this  knowledge  are  not  so  great 
but  that  it  can  be  easily  acquired  by  any  one  having  an  ordi- 
nary understanding  of  the  principles  upon  which  it  is  based, 
or  sufficient  intellect  to  comprehend  the  commonest  elements 
of  chemistry. 

From  carelessness  or  ignorance  many  errors  are  com- 
mitted, and  much  time  and  labor  are  lost  by  mistakes  that 
the  correct  attainment  of  the  manner  of  chemical  analysis 
or  assay  of  the  alkalies  would  tend  to  avoid.  The  acquire- 
ment of  a  thorough  chemical  knowledge  is  scarcely  to  be 
expected  of  men  whose  time  has  to  be  employed  in  another 
direction  :  yet  it  is  most  important  that  the  chemical  action 
of  the  materials  applicable  to  the  fabrication  of  soap  should 
be  well  studied.  To  this  end  the  author  will  try  to  give 
the  most  simple  and  correct  methods  for  the  testing  of  the 
alkalies. 

The  alkalies  of  commerce  are  never  pure,  but  contain, 
besides  carbonates,  sulphates,  sulphites,  chlorates,  etc.,  so  that 
the  object  of  alkalimetry  is  to  determine  the  percentage  of 
caustic  or  carbonated  alkali  a  potash  or  soda  of  commerce 
may  contain.  The  principles  of  this  test  are  based  upon  the 
law  of  equivalents,  which  is  illustrated  elsewhere,  and  which 
means  that  a  certain  definite  weight  of  a  reagent  is  required 
to  saturate  or  neutralize  an  equivalent  of  a  base.  So,  on 
the  variations  in  the  quantity  of  pure  alkali  contained  in 


ALKALIIilETRY. 


167 


the  alkalies  of  commerce  depend  their  value,  and  the  amount 
necessary  to  use  in  solution  to  boil  or  make  a  soap. 

To  determine  the  quantity  of  real  alkali  the  lyes  may 
contain,  it  is  obvious  that  a  rapid  and  easy  method  is  very 
desirable,  and  among  the  numerous  means  to  this  end  it  is 
the  desire  of  the  writer  to  give  the  least  elaborate,  and  to 
simplify  the  description  as  much  as  possible. 

The  hydrometer  of  Baume,  though  a  valuable  instru- 
ment in  determining  the  density  of  a  fluid,  will  not  give  an 
accurate  test  of  the  strength  of  a  caustic  alkali,  as  all  the 
impurities  dissolved  with  the  solution  tend  to  make  it  heavier. 
So  it  would  show  but  an  imperfect  result, for  it  would  not  indi- 
cate the  amount  of  alkali,  but  the  density  or  specific  gravity 
of  the  fluid,  which  might  be  a  solution  of  culinary  salt,  or 
a  mixture  of  several  salts,  and  it  is  a  useful  instrument  only 
when  the  proper  preparation  has  been  given  to  the  lyes,  and 
they  have  been  brought  into  a  state  of  causticity  and  purity 
necessary  for  the  saponification  of  fats.  Then  it  is  exceed- 
ingly handy.  To  ascertain  the  true  condition,  other  and 
more  scientific  tests  are  necessary. 

Analysis  hy  Measure^  or  Volumetric  Analysis, 

Though  a  simple  process  to  the  expert,  it  yet  requires 
some  practice  and  skill,  for,  as  we  have  remarked,  the  alka- 
lies of  commerce  are  contaminated  with  so  many  foreign  in- 
gredients that  their  testing  requires  great  exactness,  and 
moreover,  the  methods  of  different  chemists  vary  with  each, 
though  giving  the  same  results.  From  these  processes  we 
shall  try  and  select  the  simplest. 

Alkalimetry  was  until  quite  recently  a  purely  technical 
operation,  when  it  assumed  a  scientific  basis,  and  has  de- 
veloped into  an  almost  perfect  process,  which  simply  in  its 
entire  operation  consists  in  the  neutralization  of  the  alka- 
line base  with  an  acid  of  a  certain  strength. 

The  operation  itself  is  called  titration  from  the  acid  which 
has  a  certain  titre,  that  is,  a  certain  weight  according  to  the 
contents.    A  certain  weight  of  acid  corresponds  to  a  certain 


168 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


weight  of  alkali,  so  that  these  measures  may  finally  he  re- 
duced to  weight.  Mohr  expresses  himself  as  follows:  "But 
one  weighing  is  only  performed  where  formerly  many  had 
been  needed.  The  accuracy  of  the  one  normal  weight  is 
repeated  in  every  experiment  made  with  the  liquid  thus 
prepared.  With  one  litre  of  test-acid,  several  hundred  estima- 
tions may  be  made.  The  producing  of  two  or  more  litres  of 
test-fluid  requires  no  more  time  and  no  more  weighing  than 
one  litre.  The  weighing  can  therefore  he  performed  when- 
ever time  and  leisure  admit." 

Besides  the  acid  we  require  certain  instruments  by  means 
of  which  the  acid  is  added  to  the  solution  of  the  body  under 
investigation.  And  as  here  a  decomposition  is  always 
carried  to  its  limits,  and  not  as  in  case  of  common  analysis 
with  a  surplus  of  the  precipitation,  these  implements  must 
permit  of  a  very  regular  flowing  oft'  by  drops.  They  are 
two,  the  burette  and  the  pipette. 

The  Burette. 

This  instrument  has  been  brought  into  use  in  various 
forms,  but  we  give  the  preference  to  the  clip  (compression, 
stopcock)  burette  of  Mohr  (Fig.  3),  for  its  simplicity  and 
convenience  of  manipulation.  It  consists  of  a  straight  cylin- 
drical glass  tube,  of  not  too  thin  sides,  which  is  graduated 
into  ^  or  cubic  centimetres  (0.054  or  0.027  fluidrachm).  At 
its  lower  end  it  is  drawn  out  to  a  somewhat  distended  point 
to  allow  a  gum  tube  to  be  drawn  over  it  and  securely  fastened. 
The  india-rubber  tube  is  about  40  millimetres  (1.57  inches) 
long,  and  is,  if  necessary,  tied  with  a  strong  silken  thread.  In 
the  lower  end  a  glass  tube  drawn  out  to  a  tine  point  is  inserted, 
which  as  it  has  only  to  bear  a  certain  strain  of  the  liquid  col- 
umn while  the  compression-stopcock  is  opened  it  holds  easily 
without  any  fastening.  The  gum  tube  is  closed  by  means  of 
a  clip;  this  latter  is  made  of  brass  wire,  hard  drawn,  of  3  to 
3J  millimetres  (0.12  to  0.14  inch)  thickness.  To  this  end  the 
WMre,  which  is  shown  of  its  full  size  in  Fig.  4,  is  bent  into 
a  20  to  22  millimetre  (0.78  to  0.86  inch)  wide  circle  and  the 


ALKALIMETRY. 


169 


hammer  so  as  to  obtain  in  this  direction  more  elasticity. 
On  one  end  is  soldered  a  right  angle  piece  of  the  same  kind 
of  wire.    Upon  the  cut  off  part,  two  smaller  angles  of  the 


170 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


eame  wire  are  soldered.  In  a  position  of  rest  the  angles  are 
lying  on  each  other.  As  soon  as  we  press  upon  the  handle- 
joints  the  angles  open,  and  the  gum  tube  relieved  from 
pressure  permits  the  liquid  in  the  burette  to  flow  out. 

Fiff.  4 


If  this  gum  tube  is  sufficiently  elastic,  and  the  wire  on  the 
clip  stiiF  enough,  we  need  not  fear  that  the  tube  when  not  in 
use  will  permit  even  one  drop  of  liquid  to  flow  out.  Fig.  3 
shows  the  burette  provided  with  India-rubber  tubes  and 
clips. 

When  the  burette  is  idle  and  filled  with  the  liquid,  as  is 
often  the  case  in  technical  operations,  where  experiments  are 
so  often  repeated,  and  to  be  always  on  hand,  it  should  then  be 
closed  above,  that  no  evaporation  may  take  place.  Such  a 
stopper  can  be  easily  replaced  by  a  toy  marble.  That  these 
marbles  may  fit  more  tightly,  the  burette  has  a  facet-like 
opening,  but  a  conical  glass  plug  may  serve  this  purpose 
better ;  such  stoppers  are  tighter  and  are  sufficient  to  close  it. 

When  as  in  soap  manufactories  alkalies  are  mostly  to  be 
investigated,  one  burette  is  amply  sufficient  for  the  acid, 
but  it  is  a  great  convenience  to  place  a  second  burette  with 
a  normal  potash  solution  along-side  of  it.  Thus  a  hasty 
analysis  might  be  easily  rectified  by  adding  alkali  to  the 


ALKALIMETRY. 


171 


red  titrated  liquid  until  it  again  assumed  a  pure  blue,  and 
taking  the  used  cubic  centimetres  of  alkali  from  those  of 

Fig.  5. 


the  acid.  The  two  burettes  represented  in  Fig.  3  serve 
best  for  this  purpose.    But  besides  this  it  is  best  in  case  of 


172 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


breaking  one  to  have  several  on  hand,  especially  in  places 
where  it  is  impossible  to  obtain  a  new  one  at  once. 

The  burette  ready  for  immediate  and  continuous  use  is 
represented  by  Fig.  5. 

The  Pipette. 

This  very  useful  instrument  is  also  a  straight  glass  tube, 
which,  except  about  40  millimetres  (1.57  inch)  at  its  upper 
end  and  5  millimetres  (0.20  inch)  at  its  lower  end,  is  divided 
in  its  entire  length  into  or  |  cubic  centimetres  (0.027  or 
0.054  fluidrachm).  Pipettes  which  hold  20  cubic  centi- 
metres (5.40  fluidrachms)  are  chosen  of  a  somewhat  wider 
diameter  so  that  they  may  not  be  too  long,  and  then  they 
are  commonly  divided  into  J  cubic  centimetres  (0.054  flui- 
drachm). In  soap  manufactories  two  pipettes  are  usually 
sufficient  for  all  purposes,  divided  in  y'^-  or  I  cubic  centime- 
tres (0.027  or  0.054  fluidrachm),  and  of  10  cubic  centimetres 
(2.7  fluidrachms)  capacity. 

For  use,  the  pipette  is  filled  somewhat  above  the  0  degree, 
by  a  gentle  suction,  while  the  point  is  dipped  into  the  liquid 
and  then  quickly  closed  with  the  moistened  ball  of  the  index 
finger  of  the  right  hand.  By  moving  the  finger  slightly  so 
much  of  the  liquid  is  permitted  to  run  out  until  it  stands 
precisely  at  0.  In  order  to  notice  this  more  plainly,  the 
pipette  is  held  against  a  light  surface.  The  lowest  point  of 
the  convex  segment  must  just  touch  the  division  line.  To 
let  the  drops  fall  ofi*  easily  and  be  as  small  as  possible,  the 
point  of  the  pipette  is  covered  Avith  paraffin. 

In  general  the  work  with  the  pipette  is  more  convenient 
than  with  the  burette.  It  is  held  perpendicularly  in  the 
right  hand,  taking  hold  of  the  beaker  with  the  left  hand,  or, 
what  is  still  better,  a  large  porcelain  cup,  letting  so  much 
flow  out  of  the  pipette  until  the  liquor  appears  of  the  desired 
color. 

Pipettes  are  useful  instruments  to  quickly  measure  oflf  cer- 
tain larger  or  smaller  quantities  of  liquid,  to  which  end  a  sys- 
tematic series  of  all  sizes  should  be  on  hand  of  1, 2, 5, 10, 20, 50, 


ALKALIMETRY. 


173 


and  100  cubic  centimetres.  The  smaller,  from  1  to  20  cubic 
centimetres,  have  the  shape  shown  in  Fig.  6.  The  body  has 
such  a  diameter  that  the  pipette  may  be  inserted  into  a 
wide-mouthed  bottle  to  withdraw  the  liquid  therefrom.  The 
larger  pipettes  receive  either  the  shape  as  in  Fig.  7,  or  Fig.  8 ; 


Fi^r.  6.  Fig.  7.  Fig.  8. 


the  former  are  less  liable  to  break,  but  the  latter  need  not  be 
80  long.    The  upper,  thinner  part,  the  stem,  has  at  a  cer- 


174  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


tain  part  the  mark  for  the  contents  for  which  the  pipette  is 
arranged.  In  emptying  it  the  pipette  is  permitted  to  run 
out  completely,  and  it  is  well  to  hold  its  point  against  the 
moist  side  of  the  receiving  vessel,  from  which  the  drop  hang- 
ing on  the  point  is  removed,  or  we  touch  with  the  point  the 
surface  of  the  poured-out  liquid. 

The  large  pipettes  permit  in  many  cases  a  great  saving  of 
labor.  Supposing  we  would  ascertain  several  ingredients  in 
one  lye  (alkali,  chlorides,  sulphates,  etc.),  in  separate  opera- 
tions, then  this  lye  is  brought  into  a  measured  glass  which 
holds  about  500  cubic  centimetres  (16.9  fl.  ozs.)  up  to  the 
mark,  when  by  means  of  a  pipette  100  cubic  centimetres  (3.38 


Fig.  9.  Fig.  10. 


fl.  OZS.) are  taken  from  it.  We  have  then  accurately  the  tilth 
part  of  the  matter  contained  in  the  entire  liquid,  for  instance, 
the  alkali,  which  still  leaves  J  for  testing  for  chlorates  and 
sulphates,  etc. 


ALKALIMETRY. 


175 


Flasks. 

Measure-flasks  are  of  very  extended  application  :  they  are 
used  of  all  sizes,  from  100  cubic  centimetres  (3.38  fl.  ozs.)  to 
the  litre  or  1000  cubic  centimetres  (33.8  fl.  ozs.).  The  latter 
and  also  the  500  cubic  centimetre  (16.9  fl.  ozs.)  flask,  which 
is  equal  to  J  kilogramme  (1.1  lb.),  are  most  often  used.  They 
serve  for  measuring  greater  quantities  of  liquids  than  the 


Fig.  11. 


full  pipettes.  Their  usual  form  is  shown  in  Figs.  9  and  10. 
The  sizes  most  suitable  are  1  litre,  1000  cubic  centimetres 


176  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


(33.8  fluidounces),  100  cubic  centimetres  (3.38  fluidounces). 
They  have,  on  the  neck,  a  mark,  up  to  which  they  are  filled 
with  the  test-liquids  ;  upon  their  side  they  carry  the  figures 
of  their  capacity.  Of  the  smaller  sizes  a  large  number  are 
kept  at  disposal. 

Cylinders  for  Mixing. 

These  two  utensils  are  principally  used  for  producing  the 
titrimetrical  liquids  (acids  or  alkalies).  The  mixing  cylin- 
der has  a  stopper  of  glass,  and  is  graduated  from  10  (0.33  11. 
oz.)  to  1000  cubic  centimetres  (33.8  fl.  ozs.),  see  Fig.  11.  These 
cylinders  are  represented  in  Fig.  12,  and  also  graduated  from 


Fig.  13. 


100  (3.38  fl.  ozs.)  to  1000  cubic  centimetres  =  1  litre  (83.8  fl. 
ozs.).  Their  stoppers  are  also  made  of  glass.  The  most  suit- 
able size  for  mixing  cylinders  and  mixing  bottles  is  1000 


ALKALIMETRY. 


177 


cubic  centimetres  =  1  litre  (2.1  pints),  but  others  of  less 
capacity  are  also  used. 

Scales  and  Weights. 

The  most  indispensable  of  all  instruments  is  a  good,  suffi- 
ciently sensitive,  balance  or  scale,  with  the  accurate  weights 
belonging  thereto.  For  a  soap  manufactory  such  a  scale  is 
good  enough  which,  when  burdened  with  a  weight  of  4  ozs., 
will  yet  indicate  with  accuracy  when  one-half  grain  addi- 
tional weight  is  placed  upon  it.  The  absolute  correctness 
of  the  weights  is  likewise  required. 

Tincture  of  Litmus,  Cochineal  Tincture. 

To  ascertain  the  point  where,  by  the  addition  of  the  ti- 
trated acid  to  the  alkali,  which  is  to  be  estimated,  or  from 
a  titrated  alkali  to  an  acid,  neutrality  will  ensue,  litmus 
tincture  is  usually  applied,  but  in  some  instances  cochineal 
tincture  will  serve  the  same  end.  Both  show  by  the  varia- 
tion of  color  which  they  undergo  the  small  overplus  of  alkali 
or  acid  and  the  point  of  neutrality.  The  blue  color  of  the 
litmus  turns  by  dint  of  the  overplus  of  acid  into  red,  and  the 
color  of  the  acid  reddened  by  the  litmus  changes  into  blue  by 
an  excess  of  alkali.  The  tincture  of  cochineal  is  originally 
of  a  chestnut-brown  color,  which,  with  alkali,  becomes  a 
splendid  carmine  red,  and,  by  adding  acid,  receives  a  light 
brick-red  color.  Each  of  these  two  indicators — the  term  given 
to  these  tinctures — has  its  advantages  and  its  faults.  The 
tincture  of  litmus  does  not  show  the  beginning  of  neutrality, 
since  by  the  test  with  carbonated  alkalies  the  carbonic  acid 
becomes  free  and  acts  upon  the  color  of  the  litmus,  and  pro- 
duces a  coloring  which  is*  neither  red  nor  blue;  hence  the 
liquid  has  previously  to  be  warmed  in  order  thereby  to  re- 
move the  carhonic  acid.  But  this  is  troublesome  and  con- 
fusing. This  fault,  however,  the  tincture  of  cochineal  does 
not  have ;  its  color  is  in  no  wise  affected  by  the  free  carbonic 
acid,  no  warming  is  needed,  and  the  operation  may  be  per- 
formed in  one  draught.  For  investigating  the  carbonated  alka- 
12 


178  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

lies  it  is  in  a  high  degree  preferable.  But  it  is  most  suitable 
for  testing  caustic  alkalies,  especially  in  concentrated  solu- 
tion, and  some  exp  erience  is  required  to  hit  the  proper  point. 
Its  color  suffers  in  contact  with  alkalies,  a  chemical  change 
takes  place  in  consequence  thereof;  by  the  neutralization  of 
an  acid,  not  a  brick-red  color,  but  a  carmine-red  hue  appears, 
which,  by  inexperienced  persons,  may  easily  be  confounded 
with  that  caused  by  alkali.  If  it  is  intended  to  make  use  of 
the  cochineal  tincture  for  testing  the  caustic  alkalies,  it  would 
be  well  to  allow  the  lye  to  flow  upon  the  normal  acid.  The 
tincture  of  cochineal,  when  the  liquid  to  be  tested  contains 
even  a  mere  trace  of  oxide  of  iron,  is  quite  unserviceable. 
When,  however,  it  is  applicable,  it  is,  without  doubt,  cer- 
tainly much  more  sensitive  than  the  tincture  of  litmus. 

The  Preparation  of  Tincture  of  Litmus. 

Place  33J  grms.  (1.175  ozs.)  of  good  commercial  litmus  in 
a  test-tube,  pour  about  133J  grms.  (4.70  ozs.)  of  distilled 
water  on  it,  place  it  u|ion  a  heated  stove,  frequently  shaking 
it  gently.  After  a  lapse  of  from  six  to  eight  hours  the  in- 
tensely blue  liquid  is  drained  off  from  the  residuum,  to 
which  add  again  66f  to  83 J  grms.  (2.35  to  2.94  ozs.)  of  water, 
and  let  it  again  stand  in  the  warmth  for  a  short  time,  and  de- 
cant when  both  extracts  are  mixed.  The  liquid  contains  free 
carbonate  of  alkali,  which  is  a  hindrance  to  its  sensitiveness, 
and  must  be  removed.  This  is  done  best  and  most  completely 
by  boiling  the  tincture  with  about  3  per  cent,  of  the  litmus 
used  with  finely  powdered  gypsum,  and  digesting  it  for  a 
longer  period.  By  this  operation  carbonate  of  lime  is  pro- 
duced, as  well  as  sulphate  of  alkali,  which  remains  dissolved. 
This  tincture  assumes,  thus  prepared,  after  a  few  days,  a  de- 
cided lilac  shade  of  color,  but  it  is  nevertheless  as  well  for 
alkalies  as  for  acids  in  the  highest  degree  sensitive,  the 
smallest  overplus  of  the  former  making  it  a  pure  blue,  the 
smallest  overplus  of  acid  decidedly  red.  At  times  the  tinc- 
ture of  litmus  shows  the  peculiarity  of  losing  its  color  in  a 
closed  flask  and  turning  brown  ;  but.it  is  not  for  this  reason 


ALKALIMETRY. 


179 


to  be  considered  as  spoiled.  If  it  is  brought  in  contact  with 
the  air  it  again  assumes  a  blue  color. 

Tincture  of  Cochineal. 

According  to  Lucknow,  who  was  the  first  to  recommend 
this  tincture  as  an  indicator,  3  grms.  (0.11  oz.)  of  the  best 
cochineal  are  ground  and  transfused  with  a  mixture  of  50 
cubic  centimetres  (1.69  fl.  oz.)  of  alcohol  and  200  cubic  cen- 
timetres (6.76  fl.  ozs.)  of  distilled  water,  then  left  to  digest 
several  hours,  and  finally  filtered  through  lime-free  paper. 
This  tincture  has  a  dark  orange-red  color,  with  a  tinge  of 
brown  (dark  chestnut-red).  10  cubic  centimetres  (0.338  fl.  oz.) 
of  water  to  10  drops  of  the  tincture  produce  a  light  orange- 
red  fluid. 

The  phenomena  during  neutralization  are,  in  the  case  of 
tincture  of  cochineal,  dififerent  from  those  of  the  litmus, 
which,  from  the  beginning,  according  to  the  quantity  of  the 
tincture  employed,  turns  into  purple-violet  or  in  this  shade 
of  lighter  tinge,  then  gradually  becoming  carmine-violet  or 
cherry-red,  until  the  close  of  the  operation.  A  more  or  less 
orange  shade  appears,  when  the  tincture  of  cochineal  is  used. 

The  Basis  of  AlkalIxMetry. 

For  this  various  substances  have  been  proposed.  What  sub- 
stances are  used,  whether  acids  or  alkalies,  is  tolerably  un- 
important, if  they  can  be  obtained  in  their  purest  state  and  be 
weighed  oflp  with  all  possible  accuracy.  Gay-Lussac  used 
the  anhydrous  carbonate  of  soda  as  a  base,  and  neutralized 
it  with  sulphuric  acid.  If  the  necessary  care  is  observed,  the 
most  perfect  and  ample  results  for  technical  purposes  are 
reached  by  using  the  carbonate  of  soda.  The  great  tendency 
of  fresh  calcined  carbonate  of  soda  to  absorb  moisture  caused 
Mohr  to  substitute  for  it  crystallized  oxalic  acid.  Although 
oxalic  acid  combines  many  properties  which  recommend  it 
as  a  titrimetric  substance,  and  is  easily  prepared  in  a  pure 
state,  and  can  also  be  weighed  accurately,  its  application  as 


180 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


such  is  nevertheless  not  without  critical  objections,  since 
it  often  contains  more  water  than  corresponds  with  the 
formula  C2O3  +  HO,  and  moreover  is  often  not  free  from 
small  quantities  of  oxalate  of  potash  and  lime.  These  rea- 
sons caused  Fincus  to  apply  the  pure  carbonate  of  lime  as  a 
basis  for  alkalimetry,  and  tlie  suitableness  of  this  selectioii 
has  been  almost  everywhere  acknowledged. 

Pure  carbonate  of  lime  is  obtained  best  in  this  w^ay:  A 
certain  quantity  of  nitrate  of  ammonia  is  dissolved  in  ten 
times  as  much  water,  and  digested  with  an  overplus  of  hy- 
drate of  lime,  by  frequent  shaking,  for  several  hours,  theii 
filtered,  and  precipitated  either  with  carbonate  of  ammonia 
or  by  leading  into  it  a  stream  of  carbonic  acid  gas  until  all 
the  lime  combines  with  the  carbonic  acid  and  is  precipitated. 
By  evaporating  the  liquid,  the  nitrate  of  ammonia  is  reob- 
tained,  which,  in  this  manner,  can  again  be  used  for  produc- 
ing the  pure  carbonate  of  lime.  The  precipitate  is  placed 
upon  a  filter,  washed  with  distilled  water,  dried,  gently 
calcined,  and  preserved  in  a  well-closed  glass  phial,  with 
the  inscription  ''  Pure  carbonate  of  lime  suitable  for  alkali- 
metry." 

By  means  of  the  carbonate  of  lime  thus  obtained,  the  nor- 
mal acid  is  prepared.  Kitric  acid  is  to  be  recommended 
for  this  purpose,  because  it  forms  with  most  bases  soluble 
salts.    Carbonate  of  lime  consists  of: — 

1  equivalent  of  lime  =  22 

1        "        of  carbonic  acid  =  23  and  has  tlie  equivalent 

50 

Nitric  acid  consists  of — 

1  equivalent  of  nitrogen  =  14 

5        "        of  oxygen   =  40  and  Iience  lias  the  equivalent 
54 

Tbe  normal  nitric  acid  applied  in  alkalimetry  must  contain 
in  the  litre  54  grammes  (1.9  oz ),  or  exactly  so  much  anhy- 
drous acid,  that  with  50  grammes  (1  75  oz.)  of  carbonate  of 
lime  it  will  be  neutralized.    The  preparing  of  such  an  acid  is 


ALKALIMETRY. 


181 


performed  thus:  Take  a  pure  nitric  acid,  diluted  with  water, 
of  a  strength  to  suit,  and  liquid  of  ammonia,  so  fixed  that  equal 
volumes  of  acid  and  of  ammonia  are  accurately  saturated. 
^ow  weigh  accurately  2  grammes  of  pure  carbonate  of  lime, 
place  the  same  in  J  litre  flask,  pour  about  100  cubic  centime- 
tres (3.38  fl.  ozs.)  of  distilled  water  and  a  suflScient  quantity  of 
tincture  of  litmus  or  tincture  of  cochineal  on  to  it,  and  also 
add  an  accurately  measured  quantity  of  the  acid  corresponding 
with  the  ammonia,  so  that  all  the  lime  is  dissolved  and  the 
liquid  remains  plainly  of  red  color.  The  liquid  is  then  heated 
to  boiling,  in  order  to  entirely  remove  the  carbonic  acid. 
After  this  is  done  and  the  whole  is  somewhat  cooled  off,  the 
surplus  of  the  acid  is  removed  by  an  equivalent  of  ammonia, 
and  we  thus  learn,  by  deducting  the  cubic  centimetre  of  am- 
monia used  from  the  applied  cubic  centimetres  of  the  acid, 
exactly  the  quantity  of  acid  which  has  been  neutralized  by 
the  above-mentioned  carbonate  of  lime.  Since  the  acid  must 
now  have  such  a  strength  that  1000  cubic  centimetres  (33.8 
fl.  ozs.)  thereof  are  neutralized  by  50  grammes  (1.75  oz.)  of 
carbonate  of  lime;  for  2  grammes  of  carbonate  of  lime  40 
cubic  centimetres  (1.36  fl.  oz.)  of  acid  must  result.  If  now 
less  acid  has  been  used,  as  is  always  the  case,  the  acid  must 
be  thus  much  diluted  that  40  cubic  centimetres  (1.36  fl.  oz.) 
of  liquid,  that  is,  normal  nitric  acid,  are  produced,  and  accord- 
ing to  this  proportion  the  total  quantity  of  the  equivalent  of 
nitric  acid  must  be  diluted  to  correspond  to  the  ammonia. 
Supposing  we  have  750  cubic  centimetres  (25.4  fl.  oz.)  nitric 
acid,  its  equivalent  of  ammonia,  and  of  this  2  grammes 
(80.86  grs.)  carbonate  of  lime,  30  cubic  centimetres  (1  02  fl. 
oz.)  applied,  then  those  750  cubic  centimetres  (25.4  fl.  ozs.) 
must  be  diluted  to  1000  cubic  centimetres  (33.8  fl.  ozs.),  an 
operation  which  is  to  be  performed  in  the  mixing  cylinders 
or  in  the  mixing  flask. 

Inasmuch  as  1000  cubic  centimetres  of  this  acid  contain 
1  equivalent  of  nitric  acid,  they  also  neutralize  each  1  equiv- 
alent of  any  base,  respectively  alkali  or  the  quantity  of  a  com- 
bined acid,  in  which  1  equivalent  of  a  base  is  contained,  or 
they  will  neutralize: — 


182  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


equivalent  of  potash 

47.11 

grammes 

(1.6  ozs 

of  liydrate  of  potash 



56.11 

(1.96  " 

of  carbonate  of  potash 



69.11 

ti 

(2.4  " 

u 

of  soda 



31.00 

(1.1  " 

of  hydrate  of  soda 



40.00 

( ( 

(1.4  " 

of  carbonate  of  soda 

■  

53.00 

( < 

(1.8  " 

il 

of  crystallized  carb.  of  soda 

143.00 

(( 

(5  " 

li 

of  lime 

28.06 

u 

(0.98  " 

of  hydrate  of  lime 

37.00 

li 

(1.29  " 

u 

of  carbonate  of  lime 

50.00 

(1.75  " 

1  cubic  centimetre  (0  27  £L.  drm.)  of  the  nitric  acid  corre- 
sponds therefore  with — 


0.04711  gramme  (0.727  grain)  of  potash 


0.05611 

(0.87  " 

)  of  hydrate  of  potash 

0.06911 

(1.066  " 

)  of  carbonate  of  potash 

0.0310 

(0.48  " 

)  of  soda 

0.0400 

"       (0.62  " 

)  of  hydrate  of  soda 

0.0530 

(0.82  " 

)  of  anhydrous  carbonate  of  soda 

0.1430 

"       (2.21  " 

)  of  crystallized  carbonate  of  soda 

0.0280 

(0.43  " 

)  of  lime 

0.0370 

(0.57  " 

)  of  hydrate  of  lime 

0.0500 

(0.77  " 

)  of  carbonate  of  lime. 

The  following  table  contains  the  quantities  of  bases  m 
grammes,  which  are  neutralized  by  1  to  9  cubic  centimetres 
(0.27  to  2.43  fl.  drms.)  normal  nitric  acid.  It  furnishes  for 
incidental  calculations  great  assistance,  since  by  the  tenfold 
quantities  the  period  needs  only  to  be  removed  one  space  from 
right  to  left,  while  in  the  ca'^e  of  tenth  parts  and  hundredth 
parts  the  period  should  be  removed  one  or  two  spaces  from 
left  to  right ;  and  the  figures  placed  correctly  under  each 
other,  and  thus  added: — 


1 

2 

3 

4 

5 

6 

7 

8 

9 

0.01711 

0  09422 

0.14133 

0.16844 

0.23555 

0.28266 

0.32977 

0.37688 

0.42399 

Hydrate  of  potash  

0.05611 

0.11222 

0.16833  0.22444 

1 

0.28055 

0.33666 

0.39277 

0.44S88 

0.50499 

Carb.  of  potash  

0.06911 

0.13822 

0.20733  0.27644 

0.34555 

0.41466 

0.48377 

0.55288 

0.62199 

0.0310 

0.0620 

0.0930 

0  1240 

0.1550 

0.1860 

0.2170 

0.2480 

0.2790 

0.0400 

0.080 

0.1200 

0.1600 

0.2000 

0.2400 

0.2800 

0  3200 

0..3600 

Anhydrous  carb.  of  soda 

0.0530 

0.1060 

0.1.'590 

0.2120 

0.2650 

0.3180 

0.3710 

0.4240 

0.4750 

Cryst.  carb.  of  soda  

0.1430 

0.2460 

0.4290 

0.5720 

0.7150 

0.8580 

0.9010 

1.0440 

1.1870 

0.028 

0.0560 

0.084 

0.1120 

0.140 

0.168 

0.196 

0.224 

0.252 

0  037 

0.0740 

0.111 

0.148 

0.185 

0.222 

0.259 

0.296 

0.333 

0.050 

0.100 

0.150 

0.206 

0.250 

0.300 

0.350 

0.400 

0.450 

ALKALIMETRY. 


183 


If  for  instance  by  estimating  a  [lotasb  8.75  cubic  centi- 
metres (2.3 i  fluidrachms)  of  normal  nitric  acid  had  been 
applied,  it  would  be  found  by  the  above  table: — 

for  8.0  cubic  centimetres  0.5528800  gr. 
"  0.7  "         0.0483770  " 

"•0.05    "  "         0  0034555  " 


Hence  togetlier,  0.6047125  " 

a  calculation,  wliich  by  multi[)lication  of  0.069x8.75  was 
found  only  a  little  more  intricate. 

By  the  alkalimetric  test  of  lye  we  can  operate  in  a  double 
manner,  either  by  measuring  the  equivalent  in  alkali  or  the 
combination  of  tbe  same,  which  is  the  point  in  question  ; 
weighing  them  off  in  cubic  centimetres,  diluting  if  necessary 
with  water,  adding  tincture  of  litmus  or  tincture  of  cochi- 
neal and  titratino;  with  normal  nitric  acid.  The  cubic  centi- 
metres  applied  to  the  latter  acid  show  immediately  what  per 
cent,  contents  of  the  alkali  is  contained  in  the  lye.  Or  10 
cubic  centimetres  (2.7  fluidrachms)  of  the  lye  are  placed  by 
means  of  a  pipette  in  a  beaker  and  titrated  as  above  de- 
scribed with  normal  nitric  acid.  Here,  in  order  to  find  out 
the  per  cent,  contents,  the  applied  cubic  centimetres  of  nitric 
acid  must  be  multiplied  by  the  equivalents  of  the  alkali, 
or  by  the  combination  of  the  same.  The  result  is  in  both 
cases  the  same,  only  that  in  the  latter  mode  of  proceeding  a 
multiplication  becomes  still  necessary.  If,  for  example,  of  a 
caustic  lye  3.1  cubic  centimetres  (0.8  fluidrachms)  had  been 
transferred  by  means  of  a  pipette,  and  for  its  neutralization 
2.635  cubic  centimetres  normal  nitric  acid  had  been  used,  then 
this  lye  contains  2.635  per  cent,  of  caustic  soda.  If  10  cubic 
centimetres  (2.7  fluidrachms)  lye  had  been  measured  ofl:',  then 
they  would  have  required  8.5  cubic  centimetres  (2.3  flui- 

8  5  X  31  = 

drachms)  nitric  acid  for  their   neutralization  ^   

^  1000 

0.2635;  in  100  parts  hence  2.635  as  in  the  first  example. 

If  the  lye  had  to  be  investigated  as  to  its  contents  of 

hydrate  of  soda,  then  4.0  cubic  centimetres  (1.08  fluidrachm) 

would  have  had  to  be  measured  off,  and  the  same  with  soda 


184 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


or  anhydrous  carbonate  of  soda,  5.3  cubic  centimetres  (1.43 
fluidraclim),  and  in  the  case  of  crystallized  carbonate  of  soda 
14.3  cubic  centimetres  (3.86  fluidrachms).  In  that  case  the 
respective  quantities  of  normal  nitric  acid  used  would  have 
been  3.40  cubic  centimetres  (0.90  fluidrachm),  4.505  cubic 
centimetres  (1.22  fluidrachm),  and  12.155  cubic  centimetres 
(3.28  fluidrachms),  so  that  the  same  contains  3.40  per  cent, 
hydrate  of  soda,  4.505  per  cent,  anhydrous,  and  12.55  per 
cent,  crystallized  carbonate  of  soda. 

I^ORMAL  Alkali. 

As  has  already  been  mentioned  above,  it  is  in  many  cases 
serviceable  to  have  on  liand  an  alkaline  liquid  which  is 
equivalent  to  the  normal  nitric  acid.  For  such  purpose  a 
potash,  a  soda,  or  an  ammonia  solution  may  serve.  The  lat- 
ter is  preferable  to  either  of  the  other  two.  Ammonia  can 
be  obtained  in  commerce  in  an  almost  pure  state,  under  the 
name  of  water  of  ammonia,  and  can  be  bought  in  any  drug 
store.  It  absorbs  less  carbonic  acid  from  the  air,  and  hence 
keeps  unaltered  for  a  longer  period.  Some  little  ammonia 
may  indeed  evaporate;  but  since  we  have  normal  nitric  acid 
on  hand,  the  tit  re  may  be  corrected  at  any  moment.  Mean- 
while there  is  not  much  fear  of  the  evaporation  of  ammonia 
from  such  a  diluted  liquid  as  the  normal  alkali  is,  as  it  only 
holds  1.7  per  cent,  of  aidiydrous  ammonia. 

To  prepare  normal  alkali,  the  commercial  water  of  ammo- 
nia is  used,  which  contains  about  10  per  cent,  of  ammonia; 
this,  diluted  with  four  times  its  weight  of  water,  gives  a 
liquid  which  approximates  to  the  correct  titre,  1  7  per  cent., 
but  it  is  somewhat  stronger.  To  correct  this,  take  10  to  20 
cubic  centimetres  (2.70  to  5.40  fluidrachms)  nitric  acid  in  a 
porcelain  cup,  color  with  tincture  of  litmus  bright  red,  and 
titrate  with  ammonia  until  a  pure  blue  color  ensues.  In 
proportion  as  less  of  the  ammonia  has  been  used  than  10  or 
20  cubic  centimetres  (2.70  to  5.40  fluidrachms)  the  first  mix- 
ture is  diluted  with  distilled  water.  For  instance  we  had  125 
grammes  (4.40  ozs.)  ammonia  diluted  with  J  kilogramme 


ALKALIMETRY. 


185 


(l.l  lb.)  water,  and  of  tliis  liquid  used  for  20  cubic  centi- 
metres (5.40  fluidracbms)  normal  nitric  acid  18  cubic  centi- 
metres (4.86  flnidracbms),  tben  in  case  tlie  first  mixture  con- 
tained 500  cubic  centimetres  (16.9  fl.  ozs.)  we  sbould  bave  to 
add  to  tbis  55.55  cubic  centimetres  (1.87  fl.  oz.)  distilled 
water  in  order  to  obtain  an  ammonia  liquid  whicb  is  equiva- 
lent to  tbe  normal  nitric  acid. 

Tbe  testing  of  [)Otasb  is  performed  in  tbe  alkalimetric  way. 
An  average  sample  mixed  from  tbe  contents  of  an  entire  cask 
is  weigbed  off,  10  grammes  (0.35  oz.)  are  dissolved  in  a  gradu- 
ated flask  of  100  cubic  centimetres  (3.38  fl.  ozs.),  and  left  to 
settle  until  clear,  wben  10  cubic  centimetres  (2.7  fluidracbms) 
are  taken  tberefrom  for  titration  witb  nitric  acid,  adding  some 
litmus  tincture  and  tben  warmed.  Since  10  cubic  centimetres 
of  nitric  acid  correspond  to  0.6911  gramme  of  pure  carbonate 
of  potasb,  tbe  grammes  of  carbonate  of  potasb  wbicb  are 
contained  in  tbe  10  cubic  centimetres  are  found  by  multipli- 
cation, wben  tbe  used  cubic  centimetres  of  nitric  acid  are 
multiplied  with  tbe  figure  0.6911  and  tbe  product  is  divided 
by  10.  For  exam[)le,  10  cubic  centimetres  solution  of  potasb 
=  1  gramme  (15.44  grains)  potasb  bave  required  8.5  cubic 
centimetres  (2.29  fluidracbms)  nitric  acid  8.5  x  0.6911  = 
5.8743:  10x0.58743  =  58.743  grammes  or  per  cent,  of  pure 
carbonate  of  potasb.  Tbis  calculation  is  avoided  if  in  lieu 
of  10  grammes  (0.35  oz.),  6.911  grammes  (106.6  grains) 
potasb  are  weighed,  otherwise,  however,  proceeding  in  the 
described  manner;  instead  of  nitric  acid  a  solution  of  oxalic 
acid  may  be  used,  for  which  purpose  tbe  oxalic  acid  which  is 
found  in  commerce  is  amply  sufficient. 

ESTIMATON  OF  THE  AmOUNT  OF  SODA  IN  LyES  OF  PoTASH. 

For  this  we  require,  besides  tbe  normal  nitric  acid  and  the 
tincture  of  litmus,  the  following  substances:  1.  Chloride  of 
barium  ;  2.  ^Titrate  of  silver;  3.  Carbonated  oxide  of  silver  ; 
4.  Solution  of  neutral  chromate  of  potassa ;  the  latter  to 
serve  as  a  standard.  Tbese  preparations  can  be  purcbased  of 
any  druggist.    From  the  nitrate  of  silver  is  made  a  solution 


186  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


of  17  grammes  (0.59  oz  )  to  1  litre  (1.56  quarts),  which  serves 
as  normal  titre. 

6.90  grammes  (106  grains)  potash  are  dissolved  in  a  little 
water,  and  the  solution  not  being  clear  filtered,  and  the  re- 
sidue washed  out  with  so  much  distilled  water  that  100  cubic 
centimetres  (3.38  fl.  ozs.)  liquid  are  produced,  the  residuum  is 
dried,  calcined,  and  weighed.  Its  weight  is  0.068  gramme 
(1.05  grain).  Of  the  filtered  substance  10  cubic  centimetres 
(2.70  fl.  drms.)  were  titrated  with  standard  nitric  acid,  and 
thereby  the  value  of  alkali  (soda  and  potash,  if  the  first  was 
present)  and  the  carbonic  acid  ascertained.  There  were  8.99 
cubic  centimetres  (2.42  fl.  drms.)  nitric  acid,  in  all  therefore 
89.9  cubic  centimeters  (8  fl.  ozs.)  standard  nitric  acid  used, 
which  correspond  to  1.977  carbonic  acid. 

Then  we  again  take  10  cubic  centimetres  (2.70  fl.  drms.) 
of  the  potash  solution,  diluting  the  same  with  20  to  30  cubic 
centimetres  (0.67  to  1.01  fl.  oz.)  water,  neutralizing  it  with 
diluted  chemically  pure  nitric  acid,  adding  a  few  drops  of 
chromate  of  potassa,  and  titrate  with  nitrate  of  silver  until 
the  first  white  precipitate  attains  a  weak  reddish  color,  which 
it  retains.  In  all  there  are  5  cubic  centimetres  (1.35  fl.  drm.), 
consequently  50  cubic  centimetres  (1.69  fl.  oz.)  solution  of 
silver  used,  since  1000  cubic  centimetres  (1.067  qts.)  thereof, 
with  3.5  grammes  (54  grains)  of  chloride,  correspond,  there 
are  consequently  in  6.9  grammes  (106  grains)  potash  0.175 
grammes  (2.70  grains)  chloride  of  potash. 

An  additional  10  cubic  centimetres  (2.70  fl.  drms.)  are  to  be 
neutralized  by  nitric  acid,  diluted  in  water,  and  mixed  with 
chloride  of  barium.  In  lieu  of  the  sulphates  of  potash  or  soda, 
then  present,  an  equivalent  quantity  of  chloride  of  potash  or 
chloride  of  soda,  besides  a  little  surplus  of  chloride  of  barium, 
is  produced  hereby.  The  sulphate  of  barium  is  separated, 
completely  washed  out,  and  the  liquid  mixed  with  a  sufla- 
cient  quantity  of  nitrate  of  silver.  Hereby  all  the  chlorides 
are  changed  into  carbonates,  of  which  the  carbonate  of  ba- 
rium is  not  soluble  and  precipitates  to  the  bottom,  and  is 
separated  by  filtration  and  washing  out.  The  liquid  now  con- 
tains the  chloride  of  the  alkali  (as  originally  contained  in  the 


ALKALIMETRY. 


187 


potash)  as  also  the  carhonated  alkali,  formed  by  the  chloride 
of  potassium  and  chloride  of  sodium,  calculated  as  carbonic 
acid.  Only  the  latter  comes  into  consideraticm  in  our  anal- 
ysis, and  we  must  therefore,  after  having  fixed  by  titration 
with  standard  nitric  acid  the  total  amount  of  it,  or  rather 
of  the  carbonate,  now  deduct  that  quantity  which  belongs 
to  the  original  contents  of  the  potash.  Supposing  now, 
through  the  carbonated  oxide  of  silver,  there  had  been  found 
in  10  cubic  centimetres  (2.70  fl.  drms.)  of  the  solution  of 
potash,  0.022  gramme  (0.34  grain)  in  all,  hence  0.22  gramme 
(3.30  grains)  carbonate,  which  are  equivalent  to  0.355 
gramme  (5.48  grains)  chloride.  Here,  from  the  above  0.175 
gramme  (2.70  grains),  chloride  must  be  deducted,  and  we 
obtain  then  0.180  gramme  (2.77  grains)  chloride,  corre- 
ponding  to  0.1118  gramme  (1.72  grain)  carbonate,  as  an 
equivalent  for  the  sulphuric  acid  which  had  been  present. 
But  0.22  gramme  (8.40  grains)  carbonate  are  equal  to  0.40 
gramme  (6.17  grains)  sulphuric  acid,  thence  correspond  to 
0.1118  gramme  (1.72  grain)  carbonic  acid,  0.2032  gramme 
(3.14  grains)  sulphuric  acid. 

In  6.90  grammes  (106  grains)  of  the  potash  are  therefore 
found: — 

Carbonic  acid  .  1.977  grammes  (30.50  grains) 
Chloric      "  .    0.175  '     "        (  2.70     "  ) 

Sulphuric  "  .    0.2032      "        (  8.14     "  ) 

According  to  the  experiments  of  Gruneberg,  sulphuric  and 
hydrochloric  acids  always  abound  in  potash.  Calculating 
accordingly  from  the  quantity  found  the  chloride  of  potash 
and  the  sulphate  of  potash  present,  we  obtain  for  the  former — 

0.3685  gramme  (  5.68  grs.),  and  for  the  latter: 
0.8757       "       (  5.79  ) 

0.7442       "       (11.47  "  ),  these  with  the  undissolved  resi- 
due 

0.0380       "       (  1.04  "  ) 


0.8122       "       (12  51   "  )  ofthe  applied  6.90  grammes  (106 


188  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


grains)  potash  deducted  6.0878  grammes  (93.9  grains)  remain 
for  the  carbonate  salts.  If  these  were  pure  carbonate  of  pot- 
ash, there  would  be  therein  1.938  grammes  (29.92  grains),  and, 
if  pure  carbonate  of  soda,  2.027  grammes  (31.28  grains)  car- 
bonic acid  contained  therein.  We  have,  however,  above 
found  1.977  grammes  (30.51  grains)  carbonic  acid,  and  it  fol- 
lows hence,  that  the  potash  contained  also  carbonate  of  soda. 
At  the  same  time  there  are  in  the  relations  of  the  carbonate 
value  to  the  potash  and  soda  the  conditions  given,  according 
to  which  the  corresponding  quantities  of  carbonate  of  potash 
and  carbonate  of  soda  may  be  calculated. 

As,  however,  such  calculations  are  not  familiar  to  every 
person,  the  following  table  has  been  calculate^!.  It  contains 
in  the  first  column  from  1  to  100  per  cent,  progressively, 
the  corresponding  quantities  of  the  two  carbonates;  in  the 
second  the  standard  nitric  acid  in  cubic  centimetres,  which 
is  requisite  for  the  neutralization  of  1  gramme  (15.43  grains) 
of  such  a  mixture.  Inasmuch  as  our  solution  contains  in  100 
cubic  centimetres  (3.38  fl.  ozs.)  6.0878  grammes  (93.9  grains) 
carbonates  of  potassa  and  soda,  we  have,  in  order  to  possess 
100  grammes  (1543  grains)  carbonate  of  a  salt,  to  deduct 
from  the  same  16.4  cubic  centimetres  (0.55  fl.  ozs.),  and  to 
titrate  with  nitric  acid.  In  the  present  case  14.75  cubic 
centimetres  (0.50  fl.  oz.)  of  nitric  acid  were  applied,  which, 
according  to  the  table,  corresponds  with  the  value  of  6.25  per 
cent,  carbonate  of  soda,  so  that  in  6.0878  grammes  of  the 
carbonate  of  salts, 

6.254  X  6.0878      ^  oo  /re  q^?       •    n       i  . 

  =  0.38  p-ramme  (5. 86  o^rams)  carbonate  or 

100  6  V        to  ; 

soda  are  contained. 


ALKALIMETRY. 


189 


Mixture  of  carbonate  of  potash  and  carbonate  of  soda. 


Amount  of  nitric  acid 
required  for  one  gramme 
of  the  mixed  alkalies. 


1.00  grm. 

CO.,  4-  0.00  grm. 

IN  a<J, 

14  47  ccm. 

0.99 

0.01 

II 

14.51 

0.98 

0,02 

1^ 

( ( 

14.56 

0.97 

(( 

0.03 

(( 

( ( 

14  60 

0.96 

0.04 

( < 

(( 

14.65 

0.95 

(( 

0.05 

«( 

14.69 

0  94 

n 

0.06 

(1, 

14.74 

0.98 

(I 

0.07 

i( 

( ( 

14.78 

0.92 

tl 

0.08 

14.83 

0.91 

(( 

0.09 

ki 

14.87 

0.90 

t( 

0.10 

( ( 

14.92 

U.o9 

0,11 

(( 

( ( 

14  96 

0.88 

( ( 

n 

0,12 

(t 

15.00 

0.87 

u 

0.13 

15.05 

0.86 

(I 

0.14 

15.09 

0.85 

(( 

0.15 

;( 

( ( 

15.14 

0.84 

(I 

0  16 

((. 

15.19 

A  OO 

U.8d 

( (, 

(( 

0.17 

( ( 

15.23 

U  82 

i( 

(( 

0.18 

( ( 

(( 

15.28 

0.81 

n 

0. 19 

(( 

<( 

(( 

15.31 

A  OA 

( » 

n 

0  20 

( ( 

15,35 

ft  170 
U.  (if 

0.21 

(( 

15.39 

A  ryo 
U.78 

(( 

(i 

*| 

0,22 

i( 

(( 

15.44 

0  77 

(( 

0.23 

ii 

( k 

( ( 

15.48 

0.76 

11 

0.24 

(( 

15.53 

U.7o 

(( 

0  25 

( ( 

15.57 

0.74 

(( 

u 

0.26 

( ( 

n 

15.61 

A  r»o 

(( 

0.27 

n 

15.66 

A  ryci 

( ( 

(( 

0,S>8 

(( 

t( 

(( 

15.70 

U.  (I 

u 

0.29 

( ( 

15.75 

u 

0.30 

( ( 

n 

(( 

15.79 

A  an 

U.bv) 

tk 

0  31 

t( 

n 

( ( 

15.83 

0.68 

( ( 

u 

0,32 

t  i 

( ( 

15.88 

0.67 

(( 

(( 

0.33 

(( 

(( 

( ( 

15.92 

0.66 

(( 

u 

0.34 

ti 

( i 

15.97 

II 

V.  00 

i( 

0.35 

(( 

il 

ki 

16.01 

fl  fl4 

V  04 

^^ 

(i 

0.36 

fl 

16  05 

0.63 

it 

0.37 

( < 

16.10 

" 

A 

O.o2 

(( 

l( 

0.38 

n 

(( 

( I 

16.14 

'1 

A  /J1 

(( 

0  39 

(1 

16.19 

u.  uu 

( < 

yj.  4iu 

( ( 

<( 

0.59 

(I 

i( 

0.41 

u 

16.27 

( < 

0.58 

i( 

0.42 

u 

u 

a 

16.32 

0.57 

0.43 

<( 

16.36 

(( 

0.56 

(( 

u 

(( 

0.44 

(( 

u 

16.41 

0.55 

l( 

(( 

0.45 

ii 

16.45 

0  54 

it 

(( 

(( 

0.46 

u 

(; 

16.49 

u 

0.53 

u 

(( 

0.47 

u 

fi 

16.54 

0.52 

ti 

0.48 

n 

16  58 

(( 

0.51 

0.49 

16.63 

u 

0.50 

u 

(( 

n 

0.50 

u 

n 

16.67 

a 

0.49 

(( 

n 

0.51 

u 

(t 

<( 

16.71 

(( 

0.48 

u 

0  52 

(( 

(( 

16.76 

(( 

190  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Mixture  of  carbonate  of  potash  and  carbonate  of  soda. 


Amount  of  nitric  acid 
required  for  one  gramme 
ot  the  mixed  alkalies. 


0.47  grm. 

KO, 

CO,  +  0.53  grm. 
0.54  " 

NaO, 

CO, 

(t 

16.80 

com. 

0.46 

16.85 

0.45 

(( 

0.55 

tt 

1 1 

16.89 

0.44 

0.56 

1 1 

tt 

16.93 

(( 

0.43 

0.57 

1 1 

tt 

16.98 

0.42 

0. 58 

1' 

" 

17.02 

(( 

0.41 

0.59 

it 

17.07 

0.40 

u 

0.60 

tt 

tt 

17.11 

" 

0.39 

( < 

0.61 

17.15 

it 

0.38 

(( 

0.62 

17.20 

0.37 

(( 

0.63 

(( 

tt 

17.24 

0.86 

u 

( ( 

0.64 

(( 

1 1 

17.28 

(( 

0.35 

( ( 

0.65 

tt 

it 

17.33 

it 

0  34 

( ( 

0.66 

( ( 

it 

it 

17.37 

it 

0  33 

( ( 

0.67 

a 

17.41 

it 

0.32 

( ( 

0.68 

tt 

17.46 

tt 

0.31 

(( 

0.69 

i  ^ 

" 

tt 

17.50 

<t 

0  30 

( ( 

0.70 

t  4 

tt 

tt 

17.55 

0.29 

( ( 

0.71 

t  ( 

17  59 

ti 

0.28 

u 

( < 

0.  r2 

( ( 

<t 

(( 

17.63 

ti 

0.27 

( ( 

0  73 

( 4 

tt 

it 

17.67 

(( 

0.26 

0  74 

tt 

ti 

17.71 

it 

0.25 

( ( 

0.75 

t< 

it 

17.76 

it 

0.24 

u 

0.76 

( ( 

tt 

ti 

17.80 

tt 

0.23 

( ( 

0  77 

4  4 

tt 

tt 

17  84 

it 

0  22 

0.78 

<( 

it 

17.89 

it 

0.21 

u 

(( 

0.79 

(  4 

(( 

tt 

17.93 

a 

0.20 

i( 

0  80 

( ( 

i  ( 

17.97 

0.19 

(I 

(( 

A  O  1 

0.81 

it 

18.02 

0.18 

n 

0  82 

(  4 

it 

18.06 

tl 

0.17 

<  i 

0.83 

tt 

I  ( 

18.10 

tt 

0.16 

;  I 

( ^ 

0  84 

4  4 

tt 

tt 

18.15 

ti 

0.15 

" 

0  85 

(  4 

ti 

tt 

18.19 

ti 

0.14 

0.86 

it 

tt 

18.23 

it 

0.13 

't 

0.87 

tt 

tt 

it 

18.27 

ti 

0.12 

't 

0.88 

(( 

<t 

tt 

18.32 

ti 

0.11 

0.89 

<t 

t  ( 

18.36 

a 

0.10 

<( 

u 

0.90 

(( 

it 

tt 

18.40 

ti 

0.09 

(( 

(( 

'4 

0.91 

(( 

i  < 

ti 

18.45 

a 

0  08 

(( 

u 

0.92 

t  ( 

tt 

It 

18.49 

(( 

0.07 

n 

it 

0.93 

tl 

tt 

(( 

18.53 

0.06 

't 

0.94 

tt 

a 

tt 

18.58 

(( 

0.05 

il 

0  95 

(  ( 

n 

18.62 

t( 

0.04 

(. 

i  c 

0.96 

ti 

It 

tt 

18  66 

tt 

0.03 

(( 

it 

0.97 

It 

it 

(( 

18.71 

n 

0.02 

(( 

(( 

tl 

0.98 

tt 

t  ( 

it 

18.75 

ii 

0.01 

u 

tt 

0.99 

t  ( 

tt 

tt 

18.80 

it 

0.00 

<( 

it 

1.00 

tt 

tt 

18.84 

It 

If  the  hydrochloric  and  the  sulphuric  acids  in  the  chloride 
of  potassium  and  sulphate  of  potash  respectively  have  been 


ALKALIMETRY. 


191 


ascertained,  it  may  also  be  proceeded  with  thus:  by  neutraliz- 
ing a  measured  portion  of  the  filtered  potash  solution  with 
tartaric  acid,  then  adding  the  same  quantity  of  these  acids 
once  more,  and  then  eva})orating  the  wdiole  of  it  in  a  porce- 
lain saucer  in  a  w^ater-bath  till  dry,  dissolving  the  residue, 
after  it  has  assumed  the  temperature  of  the  room,  in  a 
solution  of  tartaric  acid  which  has  been  saturated  in  the 
same  temperature,  then  drying  the  same  also  over  a  water- 
bath  and  weighing  it.  There  are  formed,  when  the  neutral 
solution  of  the  tartaric  acid  salts  are  mixed  with  the  second 
equivalent  of  tartaric  acid,  acid  tartrate  of  potash  and  acid 
tartrate  of  soda,  of  which,  w^hen  they  are  dried  and  dissolved 
in  the  solution  of  tartaric  acid,  only  the  alkali  becomes  dis- 
solved, while  tartar  becomes  the  residue,  and  after  drying  is 
calculated  with  the  alkali.  If  from  this  is  deducted  the 
potash  which  is  combined  witli  the  hydrochloric  and  the 
sulphuric  acids,  then  the  remainder  will  be  that  portion 
which  is  combined  with  carbonic  acid.  Perhaps  this  latter 
method  deserves  the  preference,  since  here  at  least  the  potash 
is  directly  fixed,  but,  on  the  other  hand,  it  is  somewhat  more 
intricate. 

To  avoid  the  calculation  of  potash  in  hydrate  of  potash 
and  carbonate  of  potash,  we  give  the  following  table,  which 
has  been  calculated  for  this  purpose,  viz.: — 


192 


TECHNICAL 


TREATISE  ON 


SOAP  AND  CANDLES. 


d 

d 

d 

w 

II 

?3 

irate 

potash 

KO,HO. 

®  -S  o* 

c  oO 

II 
« 

drate 

potash 

KO.HO. 

S  oS 

II 

(Irate 

potash 

KO,HO. 

03  x;  0' 

c  -  ^ 

"© 

Ch 

5^  o  11 

i^,  o  II 

o 
Ph 

o  II 

A'o  II 

pL| 

II 

J-o  II 

•1 
i 

1.19 

1.4  / 

OO 

41.68 

40 

Ol. . 

uy 

82.17 

101.37 

o 

2.38 

O  OQ 

QA 

42.87 

Oiii.O  i 

70 
<  u 

83.36 

102.83 

Q 
O 

3.57 

4.4^ 

Q7 

44.06 

U Tk  OO 

71 

84.55 

104.30 

A 

4 

4.76 

0.  o  1 

Oo 

45.25 

72 

85.74 

105.77 

0 

5.95 

oV; 

46.44 

7S 

86.93 

107.23 

0 

7.14 

O.  OU 

4u 

47.63 

5S  73 

74 

88. 12 

i 

8.33 

1  n  07 

41 

49.82 

60.20 

75 

89.31 

Q 
O 

9.53 

1  1  7Q 

4.* 

50.01 

fil  fi7 

76 

90.50 

n 

y 

10.71 

1 Q  on 

4Q 
40 

51.20 

DO.  1 0 

77 

91.69 

1  n 
lU 

11.91 

14  0  i 

44 
44 

52.39 

64.60 

78 

93.88 

1  1 

11 

13.10 

1  ft  1  Q 
10.  lo 

4^ 

40 

53.58 

fifi  07 

79 

A  A  (\iy 

94. U7 

1  f> 

1/C 

14.29 

1  7  Art 

4fi 
40 

54.77 

fi7  5.9 

U  i  .  OO 

80 

95.26 

1  o 

15.48 

1  Q  rt7 

47 
4  / 

55.96 

fiQ  00 

U57.  UU 

SI 

O  I 

96.45 

1  A 

14 

16.67 

on 

4S 
40 

57.15 

70.47 

82 

y  4 .04 

JO 

17.86 

00  HQ 

4Q 
4y 

58.34 

71  93 

83 

no  uo 
yo.oo 

lb 

19.05 

OQ  /I7 
^0  4< 

ou 

59.53 

79  40 

84 

1  (\(\  C\A 
luU  U4 

1  < 

20.24 

OA  (»Q 

Oi 

60.72 

74  87 

85 

1  ni  OQ 
lUl.*o 

1  Q 

lo 

21.43 

Oft  AH 

,cO.  4U 

61.91 

76.33 

86 

1  AO   /I  O 

Jy 

22.62 

07  Q7 

A  l.O  i 

00 

63.11 

77.80 

87 

1  AO  A- 1 
lUo  01 

on 

23.82 

OQ  Qi. 

64.30 

79.27 

88 

■if\A 

1U4  oU 

01 

4il 

25.01 

tJv.OW 

OO 

65.50 

80.73 

89 

lUo.yy 

OO 

26.20 

QO  07 

ou 

66.69 

82.20 

90 

1  n7  1  ft 
IU4  lo 

27.39 

Q9  79 
OO.  to 

o  t 

67.88 

83.67 

OA 

/C4 

28.58 

on 

uO 

69.07 

85. 13 

OS 

29.77 

QA  A7 
oD.  0  < 

OO 

70.26 

86.63 

OA 

30.96 

OO  lo 

fiO 

71.45 

88.14 

Of? 

32.15 

OtJ.  DU 

fil 
\)  I 

72.64 

89.61 

OQ 

33.34 

41  07 

73.83 

91.10 

29 

34.53 

42.53 

63 

75.03 

92^57 

30 

35.73 

A  A  (\A 

44. U4 

04 

76.22 

Q  1  09 

y-t.  Uo 

31 

36.91 

45.53 

65 

77.41 

95.50 

32 

38.10 

47.00 

66 

78.60 

96.97 

33 

39.29 

48.47 

67 

79.79 

98.43 

34 

40.49 

49.93 

68 

80.98 

99.90 

ALKALIMETRY.  193 


We  also  append  a  table  for  soda  : — 


o 

to 

soda 

.'  eS 

CrystaHized  car- 
bonate of  soda 
NaO,CO2,10HO. 

a  NaO. 

drate  of  i 
lO  HO. 

"  ID 

tc  . 

§  °o' 

la  NaO. 

drate  of i 
iO  HO. 

xn 

m 

\ 

1.29 

1.71 

4.61 

51 

65.81 

87.19 

285.29 

2 

2.58 

3.41 

9.22 

52 

67.10 

88.90 

239.87 

3 

3.87 

5.13 

13.83 

53 

68.89 

90.61 

244.48 

4 

5.16 

6.82 

18.44 

54 

69  68 

92.82 

249.10 

5 

6.45 

8.55 

23.05 

55 

70.97 

94.08 

253.71 

7.74 

10  26 

27  66 

56 

72.26 

95.74 

258.32 

7 
< 

9.03 

11.97 

32  29 

57 

73.55 

97.45 

262.94 

g 

10.32 

13.64 

36.88 

58 

74.84 

99.16 

267.55 

9 

11.61 

15.39 

41.49 

59 

76.18 

100.87 

272.16 

10 

12.90 

17.10 

46.13 

60 

77.42 

102.58 

279.77 

11 

14.91 

18.81 

50.74 

61 

78.71 

104.29 

281.40 

12 

15.48 

20.52 

55.35 

63 

80.00 

106.00 

286.01 

13 

16.77 

22.53 

59.87 

68 

81.29 

107.71 

290.62 

14 

18.06 

23.93 

64.58 

64 

82.58 

109  42 

295.28 

15 

19.35 

25.64 

66.19 

65 

88.87 

111.18 

299.85 

16 

20.64 

27.35 

73.80 

66 

85.16 

112.84 

804.46 

17 

21.93 

29.16 

78.42 

67 

86  45 

114.55 

809.08 

18 

23.22 

30.77 

88.03 

68 

87.74 

116.26 

818.69 

19 

24.52 

32.84 

87.64 

69 

89.08 

117.97 

818.80 

20 

25.81 

34.19 

92  26 

70 

90.82 

119.68 

322.90 

21 

27.10 

35.90 

96.87 

71 

91.61 

121.89 

327.52 

22 

28.34 

37.63 

101.48 

72 

92.90 

123.10 

382.18 

23 

29.68 

39.32 

106.10 

78 

94.19 

124.81 

336.74 

24 

30.97 

41.03 

110.71 

74 

95.48 

126.52 

841.86 

25 

32.26 

42.74 

115.32 

75 

96  77 

128.28 

345.97 

26 

33.85 

44.45 

119.94 

76 

98.06 

129.94 

350.58 

27 

34.84 

46  16 

124.55 

77 

1)9.85 

181.64 

855.20 

28 

36.13 

47.87 

1^9.16 

78 

100.64 

188.85 

359.81 

29 

37.42 

49.58 

133.78 

70 

101.93 

185.07 

364.41 

80 

38*71 

51.29 

188.39 

80 

108.25 

186.77 

369.03 

31 

40.00 

53.00 

148.00 

81 

104.51 

188.48 

878.64 

32 

41.29 

54.71 

147.61 

82 

105.80 

140.19 

878.26 

33 

42.58 

56.92 

152.28 

83 

107.09 

141.90 

882.87 

34 

43^87 

58.13 

156.84 

84 

108.88 

148.61 

887.48 

35 

45.16 

59.84 

161.45 

85 

109.67 

145.82 

892.09 

86 

46^45 

61.55 

166.07 

86 

110  96 

147.08 

896.71 

37 

47.74 

63.26 

170.68 

87 

112.25 

148.71 

401.32 

38 

49.03 

64.97 

175.29 

88 

118.55 

150.45 

405.43 

39 

50.32 

66.68 

179.90 

89 

114.84 

152.16 

410.55 

40 

51.61 

68.39 

184.51 

90 

116.18 

158  87 

415.16 

41 

52.90 

70.10 

189.18 

91 

117.41 

155.88 

419.77 

42 

54.19 

71.81 

198.74 

92 

118.70 

157  29 

424.34 

43 

55.48 

73.42 

198.35 

98 

120.00 

159.00 

429.00 

44 

56.77 

75.23 

202.97 

94 

121.29 

160.71 

438.61 

45 

58.06 

76.94 

207.58 

95 

122.58 

162.42 

438.22 

46 

59.35 

78.65 

212  19 

96 

128.86 

164.18 

442.84 

47 

60.64 

80.35 

216.81 

97 

125.15 

165.84 

447.45 

48 

61.93 

82.06 

221.42 

98 

126.74 

167.55 

452.06 

49 

63.22 

83.77 

226.08 

99 

127.08 

169.26 

456.67 

50 

64.52 

85.48 

280.64 

100 

129.44 

170.79 

461.28 

13 


194 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Analysis  of  Lime, 

It  might  scarcely  appear  admissible  to  judge  from  the 
nature  of  a  small  piece  of  lime — such  as  is  needed  for  its 
investigation — and  to  draw  conclusions  as  to  the  value  of 
the  entire  bulk  from  which  this  fragment  was  taken.  An 
average  sample  should  therefore  be  chosen.  This  is  done  by 
taking  from  a  number  of  pieces  small  portions,  and  pulver- 
izing and  mixing  them  well.  From  this  mixture  of  lime 
are  weighed  oft'  2.8  grammes  (43.21  grains)  of  lime,  which 
are  placed  in  a  100  cubic  centimetre  (3.88  fl.  ozs.)  measur- 
ing flask,  slaked  with  water,  mixed  with  5  grammes  (77.15 
grains)  muriate  of  ammonia,  and  then  the  flask  filled  up  to 
the  mark  with  water.  After  the  ensuing  decomposition,  and 
when  the  liquid  has  cleared  oft*,  10  cubic  centimetres  (0.388 
fluid  oz.)  standard  nitric  acid  are  placed  in  a  porcelain 
saucer,  mixed  with  tincture  of  litmus,  and  by  means  of  a 
pipette — graduated  to  yV  cubic  centimetre  (0.027  fluidrachm) 
divisions — titrated  with  the  normal  ammonia  liquid  until 
the  appearance  of  the  blue  color.  Of  this  12.7  cubic  centi- 
metres (0.427  fluid  oz.)  are  used.  Inasmuch  as  the  consump- 
tion is  the  larger  the  more  diluted  the  liquid  is,  so  becomes 
the  proportion  in  this  instance  reversed. 

In  order  to  find  the  percentage  of  caustic  lime,  we  must 
divide  by  12.7  in  10x100  =  1000;  and  thus  obtain  78.74  per 
cent. 

In  the  case  of  another  lime,  treated  in  the  same  manner, 
there  were  used  for  10  cubic  centimetres  (0.338  fluid  oz.)  of 
nitric  acid  11.6  cubic  centimetres  (0.891  fluid  oz.)  of  the  am- 

1000 

monia  liquid;  the  same  contained  therefore  jy^^  86.2  per 
cent,  caustic  lime. 


THE  APPLICATION  OF  SOAPS. 


195 


SECTIO]^  IX. 

THE  APPLICATION  OF  SOAPS. 

Soaps  have  so  many  uses  and  are  so  well  known  that  it 
may  be  superfluous  to  attempt  to  give  all  the  difierent  uses  to 
which  they  are  applied,  but  they  may  be  divided  into  several 
classes;  thus  soaps  for  domestic  and  laundry  purposes  and 
those  most  in  common  use,  as  the  tallow  and  rosin  soaps. 
Soaps  for  toilet  purposes  are  a  numerous  class,  and  of  great 
variety  for  bathing,  shaving,  etc.,  and  the  soaps  for  manu- 
facturers or  for  technical  purposes,  and  those  used  for  dyeing, 
for  fulling,  wool-washing,  etc.,  and  also  for  lithographic 
colors  and  numerous  other  purposes  in  the  arts. 

The  soaps  for  wool-washing  and  fulling  should  be  those 
that  lather  well  and  have  a  slight  excess  of  alkali  and  be  free 
from  starch  or  resin;  the  better  classes  of  soft  soaps  are  made 
for  these  purposes.  The  soaps  used  in  dyeing  establishments 
should  be  of  a  still  better  class,  free  from  all  adulterations, 
entirely  neutral  and  without  any  free  alkali;  those  for  the 
lithographic  tints  as  perfectly  made  as  possible,  and  without 
any  culinary  salt ;  while  the  toilet  soaps  should  receive  espe- 
cial care  in  the  selection  of  the  purest  materials,  and  in  their 
manipulation  great  regard  to  the  correct  equivalents  of  the 
fat  with  the  bases  to  insure  their. neutrality,  and  the  admix- 
tures they  may  contain  should  be  such  as  are  entirely  harm- 
less in  using,  or  such  as  would  improve  their  quality  for  the 
purpose  they  are  designed  for. 

The  action  of  soaps  in  washing  is  but  little  understood, 
and  is  based  upon  their  decomposition  in  a  large  excess  of 
water.  When  a  diluted  solution  of  the  sebacic  acid  with 
alkali  is  decomposed  into  an  acid  salt,  that  being  insoluble 
floats  away  while  the  alkali  dissolves  the  grease  and  dirt. 


196 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


We  have  explained  that  soaps  are  really  acid  salts,  as  stearic 
acid  salt,  oleic  acid  salt,  etc.  Thus,  if  we  take  one  part  of 
these  salts  to  500  parts  of  cold  water,  the  diluted  caustic  pot- 
ash or  soda,  becoming  free,  acts  as  a  solvent  of  the  dirt  or 
grease,  without  injuring  the  fabric  or  the  skin  of  the  hands 
as  a  solution  of  pure  alkali  would  do.  It  thus  appears  that 
the  separated  acid  salts  afford  to  sebacic  acids  a  certain  pro- 
tection at  the  same  time  that  they  are  themselves  useful  for 
cleansing,  because  many  substances  especially  the  fats  sus- 
pend themselves  as  emulsions  in  the  water  and  can  be  rinsed 
off  with  additional  water. 

A  further  advantage  that  soap  has  in  its  applications  over 
other  detergent  matters,  is  in  its  form,  Avhich  admits  of  its 
being  used  in  any  desirable  quantity.  When  applied  with 
water  and  assisted  by  friction,  we  make  an  emulsion  of  the 
dirt,  then  by  adding  more  water  the  alkali  is  set  free  and 
exerts  its  effects,  yet  by  the  large  quantity  of  water  it  is  so 
diluted  that  it  cannot  act  destructively. 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY.  197 


SECTIOI^  X. 

THE  ESTABLISHMENT  OF  A  SOAP  FACTORY  WITH  THE 
NECESSARY  PLANT. 

Much  might  be  said  and  many  instructions  given  on  this 
important  subject  which  perhaps  would  find  but  little  direct 
a[>plication  by  the  person  intending  to  establish  a  factory  for 
making  soaps,  for  they  might  not  suit  the  conditions  of  his 
case;  yet  there  are  general  maxims  founded  upon  just 
principles  which  may  apply  to  nearly  all,  such  as — 

The  location ; 

The  building; 

The  water; 

The  plant; 

The  machinery,  etc.  etc. 

Of  the  location  it  would  naturally  be  of  advantage  to  have 
such  an  one  that  the  raw  materials  might  be  readily  and 
cheaply  obtained,  as  well  as  that  the  products  of  manufacture 
might  with  facility  be  sent  to  market.  The  location  will 
also  depend  upon  the  kind  of  soap  made,  for  certain  kinds 
may  be  needed  for  certain  localities  or  certain  materials  can  be 
procured  to  advantage  in  others  that  would  be  a  saving  in  the 
cost  of  production.  All  this  cannot  be  a  matter  for  discus- 
sion, as  eacb  manufacturer  must  naturally  be  the  best  judge 
of  where  to  establish  himself  and  what  to  make  in  order  to 
suit  the  wants  of  his  customers.  But  wherever  located  it  is 
our  province  to  give  such  hints  as  may  improve  his  facili- 
ties, control  his  expenses,  raise  the  quality  of  his  work,  and 
above  all  enhance  his  profits. 

This  industry  is  an  eminently  progressive  one,  and  there 
are  being  constant!}^  invented  many  new  kinds  of  machi- 
nery and  labor-saving  appliances,  which  tend  to  a  more 


198  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


economical  and  improved  manufacture.  This  is  particularly 
the  case  in  the  United  States,  where  new  and  convenient 
appliances  have  done  much  to  improve  the  quality  of  soaps 
generally,  while  they  serve  to  economize  time  and  labor  and 
80  cheapen  the  production. 

Concerning  the  building  much  must  depend  upon  the  space 
and  usually  a  good  deal  is  required,  as  well  as  a  large  yard. 
The  building  had  better  be  of  an  oblong  or  square  form. 
That  part  where  the  soap  is  boiled  should  have  extra  facilities 
for  carrying  off  the  steam  and  the  vapors  that  are  not  agree- 
able to  people  generally.  It  is  best  to  have  the  large  chim- 
ney situated  in  the  centre  of  the  building,  that  the  kettles 
may  surround  it.  If  they  are  to  be  heated  by  an  open  fire, 
the  furnace  is  usually  in  the  basement,  while  the  rim  of  the 
kettle  is  extended  above  the  first  floor  sufficiently  high  to 
facilitate  the  stirring.  This  arrangement  also  holds  good  for 
the  heating  by  open  fire  or  by  super- heated  steam. 

Two  large  kettles  answer  in  most  cases  for  a  large  business, 
80  that  two  other  kettles  may  serve  for  making  the  lye. 
The  tanks  for  preserving  the  caustic  lyes  are  best  made  of 
cast  iron,  and  are  very  frequently  inserted  in  the  ground. 
This  arrangement  is  in  itself  convenient,  room  is  economized 
and  the  lyes  are  always  on  hand.  They  must  be  well  covered 
and  it  is  best  to  cover  them  with  cast-iron  lids.  The  taking 
out  of  the  lyes  is  much  more  easily  performed  if  the  tank  is 
somewhat  elevated  so  that  the  lye  may  be  drawn  by  siphons 
or  by  spigots.  We  prefer  the  so-called  water  levels,  since  be- 
tween these  and  the  lye  kettle  the  apparatus  for  filtering 
the  lyes  may  be  fixed.  These  water  levels  or  pits  may  con- 
sist of  walled  and  well-cemented  vats.  It  is  much  cheaper 
to  use  barrels  sunk  into  the  ground  and  well  cemented 
inside. 

Adjoining  the  boiling  house,  there  should  be  on  the  one 
side  rooms  for  storing  the  raw  materials,  the  potash,  soda,  and 
lime,  and  the  oils  and  fats.  The  first  room  must  be  tolerably 
warm ;  the  room  for  the  fats  as  cool  as  possible.  To  keep 
the  fats  in  the  cellar  is,  on  account  of  taking  them  up  and 
down,  not  advisable,  and  in  the  building  of  a  new  factory 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY.  199 


is  easily  avoided.  On  the  opposite  side  are  situated  the 
rooms  for  the  soap,  where  it  is  cut  into  bars  after  it  comes 
out  of  the  forms,  is  dried,  and  finally  packed  for  transporta- 
tion. The  upper  rooms  are  most  desirable  for  drying  the 
soap. 

Since,  for  the  producing  of  lyes,  the  application  of  the 
purest  possible  water  is  of  the  greatest  advantage,  the  build- 
ing should  be  supplied  with  roof-gutters,  in  order  to  receive 
all  descending  rain-water  into  a  cistern,  which  should  be 
situated  adjacent  to  the  factory,  and,  by  means  of  a  force- 
pump,  the  water  should  be  carried  to  the  respective  places. 
Besides  this,  there  should  be  in  the  yard  a  well  of  good  water. 

The  folloynng  is  a  description  of  the  soap  manufactory  for 
Marseilles  Soap  of  Gontard  in  St.  Quen,  near  Paris  (France), 
— Although  in  Marseilles,  w^hich  is  favored  by  local  condi- 
tions, the  soap  manufacture  is  carried  on  on  a  very  extensive 
scale,  nevertheless  that  industry  does  not  there  excel  in  es- 
pecially good  appointments.  A  more  complete  soap  manu- 
factory is  at  St.  Quen.  This  establishment  is  situated  in  an 
open  field,  in  the  immediate  neighborhood  of  the  railway 
depot  and  the  canal  basin  of  St.  Quen,  and  is  in  immediate 
connection  with  the  Paris  belt-road,  and  this  with  all  other 
French  roads.  There  are  high  airy  rooms  on  the  ground-floor. 
The  kettles  are  of  wood  with  bottoms  of  wrought-iron  plates, 
and  fixed  in  the  ground,  extending  to  subterranean  vaults,  that 
their  lower  parts  may  be  easily  reached  to  discover  every  spot 
which  may  leak.  The  soap  is  boiled  therein  with  surcharged 
steam,  which  is  admitted  by  serpentine  pipes  fixed  in  the 
bottom.  Steam  is  furnished  from  three  boilers  of  25  horse- 
power, then  carried  through  a  system  of  drawn  tubes  (or 
conduit  pipes)  which,  by  a  special  fire,  are  heated  almost  to 
a  red-heat. 

All  labor  being  carried  on  on  even  ground,  besides  water 
and  lye  pumps,  there  is  no  especial  lifting  apparatus  necessary. 
Gontard  manufactures  only  solid  (grain)  soap,  and  its  com- 
position which  in  100  is  60  per  cent,  sebacic  acid,  6  per  cent, 
soda,  and  34  per  cent,  water,  is  kept  very  constant.  This 
soap  is  perfectly  neutral,  and  therefore  for  the  washing  of  the 


200  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


hands  and  for  technical  operations  is  excellent.  Especially 
olive-,  sesame-,  and  ground-nut  oil  are  worked  into  soap; 
the  latter  oil  is  pressed  in  the  establishnrient  itself,  the  former 
brought  from  the  south  of  France. 

Caustic  soda  lye  is  preserved  of  various  degrees  of  strength 
in  five  large,  immured,  water-tight  kettles.  By  mixing,  a  lye 
is  obtained  of  the  medium  strength,  which  is  =  10°  B.,  and 
the  dry  alkali  used  is  usually  30  per  cent,  caustic  soda,  about 
9  per  cent,  sulphate  of  soda,  6  to  8  per  cent,  sulphite  of 
soda,  4  to  7  per  cent,  carbonate  of  soda,  and  6  to  10  per 
cent,  culinary  salt,  while  the  rest  consists  of  water. 

Two  kettles  are  always  used  for  boiling  the  soap  at  the 
same  time.  In  each  are  filled  1500  litres  (330  gals.)  lye  of 
medium  strength,  which  is  gently  heated  by  the  steam 
worm.  Thereupon  the  barrels,  which  contain  in  the  aggre- 
grate  about  3500  litres  (770  gals.)  of  oil,  are  rolled  over  a 
conduit  lined  with  lead,  which  is  inclined  towards  the  boiler. 
They  are  tapped,  the  oil  runs  into  the  canal,  and  flows  thence 
into  the  kettles. 

Here  it  meets  the  tolerably  warm  lye,  and  now  the  forma- 
tion of  soap-paste  soon  takes  place.  In  this  manner  the 
combining  of  the  sebacic  acids  with  the  alkali  progresses, 
the  mass  thickens,  and,  if  after  24  to  28  hours,  the  saponifi- 
cation proves  snfliciently  advanced  and  the  caustic  soda 
amply  bound,  they  proceed  with  the  first  cutting  of  the  pan  or 
separation.  On  this  first  operation  of  saponifying  {empatage) 
success  mostly  depends. 

The  boiling  is  now  interrupted,  and  600  to  800  litres  (132 
to  176  gals.)  salted  lye  are  put  into  the  kettle,  while  the  soap 
is  pushed  together  with  a  square  piece  of  board  of  about  90 
centimetres  (3.51  inches)  long,  which  is  fastened  to  a  long 
stick,  and  thus  is  the  lye  incorporated.  The  mass  becomes 
grainy,  the  superfluous  water,  the  separated  glycerine,  and 
the  uncombined  salts  separate  as  sub-lye.  The  steam  is 
completely  turned  ott',  and  the  mass  is  left  for  a  few  hours  to 
settle,  whereupon  tbe  lye,  by  means  of  the  opening  of  a 
conical  valve  situated  on  the  bottom,  is  permitted  to  run 
off".    It  may  be  condensed,  and,  after  separating  the  salts, 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


201 


worked  up  for  glycerine,  bj  distilling  it  with  surcharged 
steam.  Should  the  soap  not  yet  be  sufficiently  pure  and 
solid,  the  ''cutting  of  the  pan"  is  to  be  repeated,  with  a 
stronger  salted  lye. 

^ow  the  process  of  boiling  is  proceeded  with.  The  soap 
receives  the  addition  of  1200  to  1400  litres  (264  to  308  gals.) 
of  good  and  strong  lye,  and  is  left  boiling  for  several  hours. 
The  soap  grains,  which  are  insoluble  in  this  strong  lye, 
thicken  still  more  and  more,  and  they  absorb  alkali  and 
separate  water.  The  culinary  salt  and  the  surplus  water  re- 
main in  the  sub-lye.  It  is  permitted  to  settle,  and  thus  but 
a  very  weak  alkali  is  drawn  off,  in  order  to  renew  the  addi- 
tion of  fresh  and  strong  lye.  This  is  proceeded  with  until 
the  soap  no  longer  absorbs  any  caustic  soda,  and  the  lye,  by  the 
longer  boiling  and  evaporation,  becomes  specitically  heavier, 
while  the  soap,  by  absorption  of  water  and  the  solution  of 
alkali  specifically  lighter.  The  soap,  thus  finished  boiling, 
has  a  characteristic  smell.  It  dissolves  in  hot  water  without 
separating  any  oily  drops,  and  gives,  when  pressed  between 
the  thumb  and  index  finger,  a  solid  touch,  and  shows  in  this 
condition  a  dark  blue-black  color  of  sulphuret  of  iron. 

If  fitted  soap  is  to  be  produced  from  it,  it  must  be  made 
more  fluid  by  adding  more  water.  A  workman  climbs  over 
a  platform,  which  is  placed  over  the  boiler,  and  pushes  the 
above-mentioned  paddle  down  to  the  bottom.  In  the  open- 
ing formed  thereby,  a  second  workman  pours  a  few  litres  of 
weak  lye  or  water.  The  first  workman  withdraws  his  paddle 
and  pushes  down  in  another  place,  and  so  on  until  800  litres 
(176  gals.)  water  have  been  consumed,  then  a  little  less  steam 
is  admitted ;  the  grains  dissolve,  and  the  muddy  impurities 
fall  to  the  bottom. 

To  produce  the  peculiar  marbling  of  the  grain  soaps,  about 
1}  kilogramme  (3.3  lbs.)  of  iron  red  or  kalkothar"  are 
mixed  with  just  as  much  strong  lye  as  is  necessary  to  dis- 
pose the  formed  precipitate  into  the  peculiar  division  of 
flames  and  stripes.  For  this  marbling  a  peculiar  skill  is  re- 
quired. If  the  soap  is  too  watery  or  if  it  cools  off  too  slowly, 
the  precipitate  settles  too  easily  and  the  marbling  is  lost. 


202  TECHNICAL  TPEATISE  ON  SOAP  AND  CANDLES. 


The  finished  soap  is  poured  by  means  of  copper  scoops 
into  the  canals  which  lead  to  the  frames,  large  basins  which 
are  about  75  centimetres  (29.4  inches)  high.  The  Ije  settles 
on  the  bottom,  and  the  hardening  occurs  in  5  or  6  days.  The 
soap  mass  is  cut  with  long  knives  into  large  blocks  which  are 
divided  by  wire  into  smaller  pieces.  The  soap,  being  still  soft, 
is  not  yet  suitable  for  shipment,  and  in  order  to  make  it  hard 
without  the  loss  of  the  latent  water  or  to  suffer  too  much 
shrinkage,  it  is  dipped  into  a  very  strong  lye,  after  which  the 
hardening  is  accomplished  by  12  or  14  days'  drying.  The 
soap  is  now  finished  and  ready  for  shipment.  The  establish- 
ment in  St.  Quen  possesses  8  soap  boilers  of  15,000  litres 
(3300  gallons)  capacity,  24  basins  for  filtering  the  lye,  and 
30  receiving  vessels.  Every  day  14,000  kilogrammes  (30,800 
lbs.)  of  soap  are  finished,  which  amounts  to  4,000,000  kilo- 
grammes (8,800,000  lbs.)  annually.  The  workmen,  40  in 
number,  cost  daily  for  wages  but  200  francs  ($40),  while  the 
value  of  the  soap  daily  produced  amounts  to  at  least  1:^,000 
francs  ($2400). 

The  market  of  Paris  is  nearly  one-half  supplied  by  this 
manufactory,  while  the  northern  provinces  are  almost  en- 
tirely furnished  by  it.  The  proprietor  of  this  establishment 
receives  his  orders  six  months  in  advance. 

Of  course  it  is  not  in  the  power  of  many  manufacturers  to 
possess  such  extensive  establishments,  yet  there  is  so  much 
of  interest  and  instruction  in  this  description,  that  for  this 
reason  we  give  the  details. 

We  have  often  mentioned  the  importance  of  pure  water  in 
this  manufacture,  as  well  for  soap  as  for  the  solution  of  the 
lyes  as  the  usual  impurities  of  water  cause  a  waste  in  both; 
for  a  fuller  treatise  on  this  matter  the  reader  is  referred  to 
another  part  of  this  work,  in  the  section  on  materials. 

In  the  arrangement  of  the  plant  of  a  soap  manufactory, 
much  must  depend  upon  the  means  at  hand,  yet  so  much 
depends  upon  the  completeness  of  the  different  implements 
and  machinery,  for  the  rapid  and  economical  production  of 
the  soaps,  that  we  must  endeavor  to  describe  all  the  most  use- 
ful and  the  latest  inventions  for  conducting  the  different  pro- 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY.  203 

cesses  with  the  greatest  facility.  We  will  precede  this  with 
illustrations  of  two  French  soap  factories  which  may  prove 
useful  as  hints. 


Fig.  13. 


First,  one  for  making  the  mottled  Marseilles  soap,  with  an 
open  fire. 

A  A.  Factory  Building. — This  building  has   the  form 


204  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

of  a  parallelogram,  the  dimensions  of  which  vary  according 
to  the  importance  of  the  manufacture.  It  is  divided  into 
three  compartments;  the  middle  one  is  occupied  by  the 
kettles,  frames,  and  lye  vats.  That  on  the  left  contains  the 
lixiviating  apparatus.  That  on  the  right  is  employed  as  a 
store-room.  A  basement  about  9  feet  below  the  first  floor 
forms  passages  and  cellars,  a  part  of  w^hich  is  occupied  by 
the  furnaces  and  rcvservoirs  of  masonry  to  receive  the  waste 
lyes  drawn  from  the  kettles  during  the  boiling  of  the  soaps. 
The  communication  with  the  first  floor  is  by  the  stairways 
KK. 

B  B.  Kettles, — It  is  in  these  kettles  that  oils  and  fatty 
matters  are  saponified,  by  means  of  caustic  lyes  of  soda. 
They  are  placed  on  a  parallel  line;  below  these  kettles  are 
passages  and  arched  cellars,  in  which  are  placed  the  furnaces 
and  masonry  vats,  to  receive  the  waste  lyes,  which  collect  at 
the  bottom  of  the  kettles  below  the  soap.  Their  capacity 
varies  from  1250  to  5000  gallons.  Their  upper  level  is  about 
3  feet  above  that  of  the  floor  of  the  cellar,  which  is  ordinarily 
paved  with  bricks  or  hard  flagstones. 

C  C.  Fireylace, — The  fireplace  is  the  space  which  separates 
the  grate  from  the  bottom  of  the  kettle.  The  space  varies 
from  13  to  20  inches,  according  to  the  capacity  of  the 
kettles.  The  inside  of  the  fireplace  is  constructed  of  good 
refractory  bricks,  and  has  the  form  of  a  truncated  cone. 

D  D.  Grate^  or  the  part  of  the  fireplace  destined  to  support 
the  fuel.  It  is  composed  of  cast-iron  bars  placed  near  each 
other,  at  the  distance  of  about  one-third  of  an  inch.  These  bars 
are  generally  one  inch  in  thickness,  so  that  the  grate  presents 
a  surface  of  draught  equal  to  one-fourth  of  its  total  surface. 
Experience  has  shown  that  these  proportions  are  the  most 
convenient  for  producing  a  complete  combustion  of  the  fuel. 

E  E.  General  chimney  into  which  all  the  products  of  the 
combustion  are  discharged.  The  higher  the  chimney  the 
better  the  draft.  Its  inside  diameter  must  always  be  pro- 
portioned to  the  total  opening  of  the  flues  of  the  furnace. 
To  hasten  or  slacken  the  combustion  in  the  furnaces,  each 
chimney  is  provided  with  a  good  register. 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY.  205 


F  F.  Ash-pan. — The  ash-pan  is  the  vacant  space  between 
the  ground  and  the  grate.  It  has  two  different  objects. 
First,  it  gives  passage  to  the  air  between  the  bars  of  the 
grate,  an  essential  condition  to  keep  up  the  fire ;  secondly,  it 
is  a  kind  of  magazine  for  the  ashes.  Its  dimensions  are  varia- 
ble, but  it  is  ordinarily  as  wide  as  the  grate.  It  is  import- 
ant not  to  let  the  ashes  accumulate  in  it,  for  in  this  case  the 
obstruction  to  the  entrance  of  air  under  the  grate  would  re- 
tard the  combustion. 

G  G.  Cisterns  in  masonry  placed  under  the  kettles.  They 
are  used.to  receive  the  waste  lyes.  A  pump  placed  in  each 
cistern  is  employed  to  raise  the  lye  they  contain,  into  a  large 
masonry  or  sheet-iron  vat  placed  on  the  first  floor. 

H  H  H.  Large  masonry  vats  in  which  are  kept  separately 
the  difterent  qualities  of  oil  used  in  the  saponification. 
Their  capacity  is  very  variable — from  2500  to  12,500  gal- 
lons. They  are  ordinarily  covered  by  an  arch  of  bricks,  in 
the  middle  of  which  there  is  a  large  opening  closed  by  a 
wooden  trap-door. 

1 1.  Cellars  below  the  first  floor. 

L  L  L.  Basins  of  brick  or  stone.  They  are  used  to 
lixiviate  the  crude  soda  for  the  preparation  of  caustic  lyes. 
Their  number,  like  their  capacity,  varies  according  to  the 
importance  of  the  manufacture.  They  are  located  on  the 
first  floor,  and  parallel  with  the  kettles  ;  immediately  below, 
large  cisterns  are  constructed,  from  six  to  nine  feet  deep, 
specially  intended  to  be  used  as  receivers  for  the  different 
lyes  obtained  by  the  lixiviation  of  the  crude  soda. 

M  M  M.  Frames  constructed  of  brick  and  cement,  which 
have  the  form  of  a  parallelogram,  and  their  height  varies  be- 
tween seventeen  and  twenty-three  inches.  The  upper  part 
must  always  be  lower  than  the  edges  of  the  kettles,  so  that 
by  means  of  a  wooden  trough,  inclined  towards  the  frames, 
the  soap,  after  being  boiled,  may  be  run  into  them.  Their 
capacity  varies  according  to  the  size  of  the  kettle.  Generally 
each  kettle  requires  three  frames,  which  are  simultaneously 
employed. 

M  M.  Store-rooms  containing  the  crude  sodas.    It  is  also 


206  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


in  this  room  that  the  sodas  are  pulverized  and  mixed  with 
the  proper  proportions  of  lime  to  form  the  carbonate  into 
caustic  soda. 

The  pulverizing  of  the  soda  is  done  in  K  The  powder 
must  not  be  too  line,  for  in  such  case  the  lixiviation  would 
be  impossible  or  very  difficult. 

Description  of  a  General  Plan  for  a  Manufactory  of  Soap 
Heated  hy  Steam.— The  application  of  steam  to  the  fabrica- 
tion of  soaps  has  become  nearly  general.  This  system  pre- 
sents advantages  so  evident,  over  the  heating  by  open  fire, 
that  it  is  now  very  generally  adopted.  In  the  following 
figure  we  give  the  plan  of  a  manufactory  in  which  all  the 
kettles  are  heated  by  steam. 

A.  Boiler  to  produce  steam. 

B.  Fireplace  provided  with  a  cast-iron  grate,  in  which  the 
fuel  is  burned. 

C.  Chimney  for  the  discharge  of  the  products  of  the  com- 
bustion. 


Fig.  14. 


D.  Dome  from  which  the  steam  is  discharged  by  means  of 
the  pipe  F  F,  into  flat  coils,  placed  at  about  one  inch  from 
the  bottom  of  the  kettle.    This  dome  is  necessary  to  prevent 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


207 


the  boiling  water  from  entering  the  pipe,  and  thence  passing 
into  the  coil. 

F  F.  Kettles  to  boil  the  soap.  Their  shape  is  the  same  as 
the  ordinary  kettles,  only  at  the  bottom  there  is  a  horizontal 
worm  in  which  steam  continually  circulates  during  the  boil- 
ing of  the  soap.  Each  worm  is  provided  with  a  waste  pipe, 
which  traverses  the  bottom  of  the  kettle  to  discharge  the 
water  of  condensation.  The  worms  are  designated  by  the 
letters  E  E,  and  the  waste  pipes  by  G  G-.  These  pipes  are 
provided  each  with  a  valve  which  is  opened  or  closed  at  will. 

H  H.  Fipes^  to  draw  off  the  lyes  from  the  kettles. 

1 1.  Cisterms  of  masonry,  used  to  receive  the  old  lyes  drawn 
from  the  kettles. 

K  K.  Cellars,  communicating  with  the  cisterns  and  the 
furnace  by  a  stairway. 

M  M.  Foundation  of  the  kettles.  This  foundation  is  made 
of  brick  and  cement;  and  its  object  is  to  render  the  kettles 
more  solid,  and  prevent  the  loss  of  heat. 

IsT  I^.  Sheet-iron  vats,  used  to  receive  new  lyes. 

O  0.  Frames,  into  which  the  soap,  when  finished,  is  drawn. 
These  frames  are  of  w^ood,  and  open  in  four  parts.  P.  Table 
on  which  the  soap  is  divided  into  bars  and  cakes.  Q.  Dry- 
in  g-rooin,  using  hot  air  in  which  the  soap  is  dried.  Illus- 
trated and  described  elsewhere.  E-.  Ram.  This  machine  is 
used  to  mould  the  soap  by  means  of  a  copper  matrix.  A 
heater  for  superheating  the  steam  is  now  very  customary, 
and  has  its  advantages. 

The  advantages  of  the  system  by  steam  may  be  summed  up 
in  the  following  points :  1.  Economy  in  fuel,  since  several  ket- 
tles can  be  heated  by  the  same  fire.  2.  Facility  and  rapidity 
in  the  work.  3.  Products  of  a  quality  superior  to  those  ob- 
tained by  heating  with  an  open  fire.    4.  Economy  of  labor. 

The  indispensable  necessity  of  water  in  soap  factories,  either 
for  the  preparation  of  lyes,  or  the  cleaning  of  the  apparatus, 
must  determine  the  manufacturer  to  establish  his  factory 
near  a  stream  of  clear  and  limpid  water.  This  condition 
ought  to  be  attended  to,  whenever  circumstances  will  permit 
it,  for  it  is  of  great  importance  in  the  fabrication.    In  case 


208  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


well  water  has  to  be  used,  it  will  be  more  economical  to  use 
a  pump  than  to  draw  by  hand.  Then  it  will  be  convenient 
to  prepare  a  large  cistern  below  the  surface  of  the  ground, 
and  to  have  it  full  at  all  times,  for  the  various  uses  of  the 
manufacture. 

The  drying-room  mentioned  we  here  illustrate  in  the  an- 
nexed cut,  and  remark  that  all  soaps  do  not  require  drying, 
but  many  do,  and  a  drying-room  is  very  necessary — ojie  with 
warm  air  or  a  steam  heat,  or  one  well  ventilated  hy  air.  The 
latter  does  not  require  any  heating  apparatus,  but  can  be  used 
only  in  fine  weather.  It  is  generally  established  in  the  upper 
story  of  the  building,  where  the  air  circulates  freely.  Shelves 
or  racks,  on  which  are  placed  the  pieces  of  soap  to  be  dried,  are 
fixed  in  the  room,  eight  or  ten  inches  apart,  one  above  the 
other;  this  separation  has  the  advantage  of  accelerating  the 
drying  of  the  soap,  by  putting  it  in  contact  with  a  greater 
mass  of  air;  the  desiccation  is  more  rapid  when  the  tempera- 
ture of  the  air  is  elevated.  This  mode  of  drying  is  incontest- 
ably  the  most  economical,  because  it  does  not  require  either 
apparatus  or  fuel;  it  is  also  the  most  regular  and  the  best  for 
the  drying  of  soaps,  and  it  may  be  used  whenever  circum- 
stances will  permit;  unhappily  it  is  subject  to  the  variations 
of  seasons  and  weather  so  frequent  in  our  climate.  The  dry- 
ing-rooms with  warm  air  have  the  advantage  of  being  used 
at  all  seasons.  In  many  manufactories,  the  drying-room  con- 
sists of  a  more  or  less  large  room  around  which  shelves  pro- 
vided with  trays  are  disposed,  and  upon  which  are  placed 
the  pieces  of  soap  to  be  dried.  In  the  middle  of  the  room  is 
a  stove  heated  with  wood  or  coal.  The  temperature  must 
not  be  above  26.6°  C.  (80°  F.);  openings  must  be  made  in 
different  parts  of  the  room  to  permit  the  air,  saturated  with 
moisture,  to  escape  freely.  This  arrangement  quickly  has- 
tens the  drying  of  the  soap.  A  temperature  of  26.6°  C. 
(80°  F.)  is  sufficient  to  dry  in  fifteen  or  twenty  hours  pieces 
of  olein  soap  destined  to  be  moulded. 

Drying-rooYti  with  Warm  Air. — The  drying  of  soaps  in 
the  free  air  cannot  be  practised  at  all  seasons,  and  has  to 
be  stopped  in  rainy  or  damp  weather.    As  for  the  drjnng 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


209 


in  a  room  heated  by  a  stove— while  this  mode  is  gener- 
ally employed,  it  presents  the  inconvenience  of  localizing 
and  causing  an  unequal  distribution  of  the  heat.  Some 
shelves  are  remote  from  the  source  of  heat — being  but  little 
affected  by  27— from  which  it  results  that  the  soap  does  not 
dry  equally  in  all  parts  of  the  drying-room.  This  is  not  the 
only  inconvenience;  stoves  often  smoke,  especially  when  first 
lighted,  and  the  smoke  stains  and  blackens  the  pieces  of 
soap.  These  different  inconveniences,  and  particularly  that 
of  the  smoke,  have  obliged  some  manufacturers  to  use  dry- 
ing-rooms heated  by  hot  air.  By  this  system,  they  completely 
utilize  the  heat  produced  by  the  fuel,  and  the  hot  air  which 
flows  into  the  room  is  always  pure,  without  either  odor  or 
smoke.  What  distinguishes  this  system  from  all  others  is, 
that  the  desiccation  of  the  soap  is  rather  produced  by  an 


energetic  ventilation,  occasioned  by  the  abundance  of  the 
hot  air  continually  renewed  in  the  room,  than  by  a  high 
temperature;  and  experience  proves  that,  in  rooms  heated 
by  a  good  stove,  it  requires  twenty-five  to  thirty  hours  to 
14 


210  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


dry  the  soap,  while  witli  a  much  smaller  expense  of  fuel  a 
treble  quantity  of  soap  can  be  dried  in  eight  or  ten  hours  in 
a  room  heated  by  hot  air.  Fig.  15  presents  a  longitudinal 
section  of  a  drying-room  with  hot  air. 

A.  Furnace  in  which  the  fuel  is  burned. 

B.  Grate. 

C.  Ash-pan. 

D.  Door  of  the  fireplace. 

E  E.  Cast-iron  flue  through  which  the  fire  and  smoke  pass 
to  the  chimney. 

F  F.  Chimney  for  the  exit  of  the  products  of  combustion. 

G.  Register  in  the  chimney,  used  to  regulate  the  draft  of 
the  fire,  and  thus  control  the  temperature  of  the  hot  air  in 
the  room. 

H  H.  Opening  for  the  introduction  of  cold  air  ;  this  air 
grows  warm  hy  circulating  round  the  furnace  A,  and  passes 
into  the  room  by  means  of  proper  apertures. 

I  1 1  I.  Walls  of  the  room  which  must  have  the  thickness 
of  a  brick. 

K  K  K.  Chimneys  by  which  the  air  escapes,  more  or  less 
saturated  with  the  moisture  of  the  room. 

L.  Door  by  which  the  trays,  full  of  soap,  are  introduced 
into  the  room. 

M  M  M  M.  Squares  representing  the  pieces  of  soap  to  be 
dried. 

N,  Vacant  space  between  the  trays  and  the  bottom  of 
the  room. 

0  0  0  0.  Vent  holes  in  the  masonry  which  traverses  the 
room  in  all  its  length,  and  which  is  provided  with  many 
openings  to  allow  the  hot  air  to  pass  into  the  room. 

P  P  P  P  P.  Stone  or  brick  foundation  on  which  the  room 
is  built. 

The  manner  of  using  this  drying-room  is  very  simple. 
After  filling  the  trays  with  pieces  of  soap,  they  are  introduced 
into  the  room  by  the  door  L  ;  the  door  is  closed,  and  the  fire 
lighted.  The  cold  air  enters  by  the  openings  H  H,  grows 
warm  by  circulating  around  the  furnace,  and  flows  continu- 
ally into  the  room  by  the  openings  0  0  0.  The  temperature 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


211 


must  not  be  too  high  but  must  be  kept  between  26.6°  C. 
(80°  F.)  and  30°  C.  (86°  F.).  With  an  ordinary  room,  it  is 
possible  to  dry  20,000  pounds  of  soap  in  a  day. 

Kettles.— li\  our  description  of  the  necessary  plan,  the  first 
item  should  be  the  kettles,  which  are  of  various  kinds. 
Kettles  are  vessels  in  which,  by  means  of  heat,  the  manufac- 
turer combines  fatty  bodies  with  lyes  of  potash  or  soda  to 
form  soap.  Their  dimensions  vary  according  to  the  quantity 
needed.  It  is  always  advantageous  to  operate  with  large  ket- 
tles, because  they  present  a  greater  economy  of  labor,  fuel, 
and  lyes  than  the  small  ones.  As  for  the  capacity,  we  have 
ascertained  that,  for  the  treatment  of  every  100  pounds  of 
fatty  matter,  we  require  a  capacity  of  about  87|  gallons, 
thus:  to  saponify  1000  pounds,  a  kettle  of  a  capacity  of  375 
gallons  ;  for  2000  pounds,  750  gallons  ;  and  for  3000  pounds, 
from  1000  to  1125  gallons,  which  represents  the  ordinary 
size  of  the  kettles  of  Marseilles.  Whatever  are  their  dimen- 
sions, these  kettles  have  always  a  circular  form,  and  gradu- 
ally widen  up  to  the  top,  so  as  to  form  a  cone.  Some  have 
flat  bottoms,  others  have  convex  or  concave  bottoms.  Ex- 
perience has  shown  that  the  latter  arrangement  is  the  best, 
and  the  most  convenient  for  the  work.  Whatever  is  their 
capacity,  they  are  always  provided  at  their  lower  part  with 
a  pipe,  with  valve  used  to  draw  off,  after  each  operation,  the 
sub-lyes  collected  under  the  soap. 

Masonry  Kettles. — At  Marseilles  nearly  all  the  kettles  of  soap 
manufacturers  are  made  of  masonry,  except  the  bottom,  which 
is  of  copper  or  sheet  iron.  The  most  essential  condition  for  the 
construction  of  such  a  kettle  is  to  establish  it  on  a  s^ood  solid 
foundation.  This  foundation  is  covered  with  a  thick  mass 
of  masonry,  constructed  of  good  materials,  which  is  rendered 
tight  with  hydraulic  mortar,  a  little  soft,  so  that  it  may  pene- 
trate into  all  the  interstices  of  the  mass  ;  by  which  means  the 
infiltrations  of  liquid  are  rendered  impossible.  The  kettle  is 
afterwards  built  on  this  mass,  beginning  at  the  hearth  and 
the  surrounding  w^alls,  to  which  a  thickness  is  given  propor- 
tioned to  the  capacity  of  the  kettle.  When  the  level  is 
reached  on  which  the  bottom  of  the  kettle  has  to  rest,  it  is 


212  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


important  to  employ  materials  of  the  best  quality,  and  the 
least  apt  to  be  destroyed  by  the  action  of  heat  and  lyes. 
Some  stones  are  not  good  for  these  kinds  of  construction, 
because  the  heat  quickly  injures  them.  Good  stone  must  be 
used  for  the  outside  walls.  As  for  the  inside  of  the  kettle, 
it  is  always  formed  of  a  thick  counter  wall,  of  hard  and 
well-burned  bricks,  and  of  pozzuolana  cement,  employed 
with  a  certain  quantity  of  fine  sand.  It  is  very  important 
to  fill  all  the  interstices  exactly,  for,  independently  of  the 
loss  of  material,  they  would  have  the  effect  of  accelerating 
the  destruction  of  the  masonry.  To  preserve  the  kettle,  it 
is  surrounded  outside  with  hoops  of  very  thick  iron. 

It  is  by  these  precautions  that  great  solidity  is  given  to 
these  kettles.  It  is  true,  their  construction  is  costly,  and 
they  require  frequent  repairs,  but  these  inconveniences  are 
well  repaid  by  the  advantages  they  present.  The  superiority 
attributed  to  these  kettles  over  those  made  of  metal,  is  gen- 
erally recognized  by  the  manufacturers  of  Marseilles,  who 
use  no  others.  Besides  the  advantage  of  better  retaining 
the  heat  of  the  mass  during  the  saponification,  they  are  said 
to  have  that  of  not  coloring  the  pastes,  as  is  done  by  metal 
kettles.  We  do  not  know  if  there  be  any  foundation  for 
this  assertion,  but  we  can  afiirm  that  very  white  soaps  are 
prepared  in  cast-iron  or  sheet-iron  kettles  ;  then,  if  the  alter- 
ation of  the  whiteness  and  puritj^  of  the  pastes  were  due  to 
the  use  of  metallic  kettles,  necessarily  colored  soaps  would 
have  been  obtained,  since  these  kettles  were  the  only  ones 
used ;  but  it  is  not  so — it  is  sufficient  to  see  fine  white  soaps 
manufactured  in  such  kettles,  to  be  assured  that  there  is  no 
foundation  for  the  statement.  The  only  condition  to  be  ob- 
served, is  to  keep  the  kettles  always  clean  and  dry,  to  pre- 
vent the  formation  of  oxide  of  iron,  which,  by  combining 
with  the  soap,  would  communicate  to  it  a  yellow  coloration. 

Cast-iron  Kettles. — Cast-iron  kettles  are  not  much  used  in 
soap  manufactories,  because  they  are  more  costly  than  those 
of  sheet  iron,  and  also,  because  it  is  very  diflicult  to  have 
them  of  a  large  capacity,  made  of  a  single  piece.  In  France 
they  are  used  only  in  small  manufactories,  but  in  Belgium 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


213 


and  England  their  use  is  more  general.  The  first  care  to  be 
taken  in  purchasing  such  a  kettle,  is  to  choose  it  without 
defects,  and  as  thin  as  possible,  for  experience  has  shown  that 
in  this  state  it  resists  the  action  of  fire  better  than  when 
thicker.  For  the  same  reason  soft  cast  iron  must  be  prefer- 
red to  hard.  The  first  has  a  fine  and  soft  grain,  and  can  be 
more  easily  filed.  It  presents  less  inconvenience  than  the 
hard,  brittle  cast  iron,  and  is  capable  of  lasting  much  longer 
than  the  latter  Indeed,  a  soft  cast-iron  kettle  may  last 
a  very  long  time  when  well  managed,  besides,  when  warm, 
it  requires  very  little  fuel  to  keep  up  the  heat. 

Sheet-iron  Kettles. — These  kettles  are  now  generally  used 
in  nearly  all  the  soap  manufactories.  For  a  long  time  it  was 
diflicult  to  construct  them,  but  since  the  progress  in  the  me- 
chanic arts,  they  have  been  constructed  with  great  perfec- 
tion. When  a  sheet-iron  kettle  is  made,  the  dimensions  must 
be  calculated  according  to  the  quantity  of  soap  to  be  manu- 
factured. As  we  have  said  before,  for  every  100  lbs.  of  fatty 
matter,  it  requires  a  capacity  of  37J  gallons ;  starting  from 
this  base,  the  maker  will  always  succeed  in  giving  to  the 
kettle  the  capacity  necessary  for  the  work  for  which  it  is  in- 
tended. As  for  the  thickness  of  the  metal,  it  varies  accord- 
ing to  the  capacity  of  the  kettle.  For  a  kettle  of  750  to 
1000  gallons,  the  iron  should  have  3  millimetres  (0.11  inch) 
of  thickness  for  the  lateral  sides,  and  4  to  5  millimetres  (0.15 
to  0.19  inch)  for  the  bottom.  All  the  solidity  of  such  a 
kettle  depends  entirely  on  the  riveting;  however,  as  well 
riveted  as  a  kettle  may  be,  it  often  happens  that  the  first 
time  it  is  used  it  allows  a  little  liquid  to  escape,  but  soon 
the  soap,  by  stopi»ing  all  the  crevices,  completely  prevents  the 
leaking. 

Heating  of  Kettles  by  Fire. — In  the  heating  of  ordinary 
kettles  by  fire,  the  furnaces  are  constructed  so  as  to  absorb 
the  most  of  the  heat  produced  by  the  fuel,  by  applying  at 
first  the  heat  under  the  bottom  of  the  kettle,  and  directing 
it  afterwards  around  the  sides,  before  losing  it  in  the  chim- 
ney. In  soap  kettles,  on  the  contrary,  a  great  part  of  the 
heat  developed  'by  the  fuel  is  lost,  because  these  kettles  can 


214 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


be  heated  only  at  the  bottom,  so  as  not  to  burn  the  soap, 
which  would  be  the  case  if  the  heat  circulated  around  the 
sides.  iTotwithstanding  the  imperfection  of  this  kind  of 
construction,  and  the  enormous  loss  of  fuel,  experience  has 
demonstrated  that  it  cannot  be  modified  without  great  in- 
convenience. To  diminish  as  much  as  possible  the  loss  of 
heat,  it  is  necessary :  1.  That  the  fireplace  should  be  right  in 
the  central  axis  of  the  kettle.  2.  That  the  lining  of  the 
hearth  should  be  of  refractory  brick,  in  order  that  the  heat 
may  be  thrown  back  below  the  bottom  of  the  kettle.  3. 
That  the  fuel  which  produces  the  most  intense  heat  with  the 
least  flame  should  be  used;  hence  hard  coal  should  be  selected. 
4.  That  the  openings  through  which  the  products  of  the 
combustion  enter  the  chimney  should  possess  together  the 
same  surface  as  the  grate,  experience  having  shown  that  this 


Fig.  16. 


is  the  best  arrangement  for  obtaining  a  good  draft  and  effect- 
ing  a  complete  combustion  of  the  fuel.  It  is  by  fulfilling 
these  conditions  that  the  greatest  amount  of  coal  is  utilized 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


215 


in  heating  the  kettles.  Bat  to  obtain  this  result,  it  is  essen- 
tial to  have  a  well-constructed  furnace,  with  all  the  recent  im- 
provements.   The  furnace  must  be  very  dry  before  using  it. 

The  figure  (Fig.  16)  represents  a  kettle  heated  by  an  open 
fire. 

The  sides  are  composed  of  brickwork  erected  and  lined 
with  cement.  The  upper  part/,/,/,/,  which  never  comes 
in  contact  with  the  fire,  and  is  intended  to  afford  space  for 
the  soap  to  rise,  expands  in  the  form  of  a  cone.  The  fire- 
place B,  is  separated  from  the  ash-pit  H,  by  the  grate  r.  The 
fire,  after  having  heated  the  bottom  of  the  pan,  passes  by  the 
flue  ^,  ^,  ^,  half  round  the  side  of  the  pan  into  the  chimney  A. 
This  is  accessible  for  the  purpose  of  cleaning  by  the  door  x  ; 
the  soot  is  thrown  into  the  pit  L.  A  tube  with  a  cock  leads 
from  the  lowest  part  of  the  pan  for  the  removal  of  the  spent 
lye.  The  whole  of  the  pan  is  sunk  into  the  floor  of  the 
boiling  house,  which  is  made  of  planks,  stone,  or  iron  plate, 
in  such  a  manner  that  the  brickwork  of  the  upper  part  pro- 
jects to  about  three  feet  above  the  floor. 

Heating  of  the  Kettles  by  Steam. — The  most  important  in- 
vention introduced  into  the  heating  of  the  kettles,  is  incon- 
testably  the  heating  by  steam.  For  a  long  time  numerous 
experiments  were  made,  but  it  is  only  within  about  fifty 
years  that  this  new  system  has  been  advantageously  applied. 
The  first  manufacturers  who  used  steam  discharged  it 
directly  into  the  mass  of  the  soap;  the  result  was  that  the 
water  produced  by  the  condensation  of  the  steam  consider- 
ably lowered  the  degree  of  the  lyes  used  to  saponify  the  fatty 
bodies.  They  were  then  under  the  necessity  of  using  more 
concentrated  lyes.  Soon  after,  other  manufacturers  —  to 
obviate  the  above  inconveniences — conceived  the  idea  of 
causing  the  steam  to  circulate  in  the  kettle,  within  a  double 
casing,  in  such  a  manner  that  water  produced  by  the  con- 
densation of  the  steam  should  not  mix  with  the  lyes,  and 
weaken  their  degree.  This  system  is  still  followed  in  some 
manufactories,  but  it  has  the  inconvenience  of  heating  the 
sides  of  the  pan  too  much,  and  the  bottom  not  enough.  The 
result  is  that  the  ebullition  is  never  very  regular,  and  is 


216 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


more  pronounced  on  the  sides  than  in  the  centre.  Now,  in 
new  manufactories,  pans  with  a  double  casing  are  suppressed, 
and  the  soap  is  heated  directly  by  means  of  a  flat  worm  of 
strong  wrought  iron,  placed  at  about  3  to  4  inches  from  the 
bottom,  and  in  which  the  steam  circulates.  This  arrange- 
ment— as  simple  as  it  is. ingenious,  produces  the  best  results, 
and  the  heating  is  so  rapid  that  it  requires  only  half  an  hour 
to  boil  a  kettle  containing  1000  pounds  of  soap,  while  the 
heating  by  an  open  fire  will  require  from  3  to  4  hours.  This 
advantage  is  not  the  only  one  this  system  presents;  it  enables 
us  to  heat  with  a  single  boiler,  and  consequently  with  the 
same  furnace,  several  pans  at  a  time,  which  presents  a  notable 
economy  in  fuel,  time,  and  labor.  There  is  no  chance  to  burn 
the  soap,  as  in  heating  with  an  open  fire. 

The  use  of  superheated  steam  presents  greater  advantages 
than  those  obtained  by  ordinary  steam.  Experience  has 
shown  that,  by  the  use  of  superheated  steam,  the  operation 
is  more  rapid,  and  the  expense  in  fuel  greatly  diminished. 
We  give  a  representation  of  the  whole  arrangement,  consist- 
ing of  three  caldrons,  one  for  white,  anf)ther  for  yellow,  and 
a  third  for  palm,  and  the  finer  soaps.  G  designates  the  main 
pipe  or  feeder,  which  is  attached  to  the  steam  boiler  W,  of 
the  establishment.  It  is  stationary,  and  generally  fitted 
against  the  wall,  immediately  above  the  kettles.  The  boil- 
ing caldrons  are  partly  of  iron  and  partly  of  wood — the 
upper  portion  or  curb  A  being  of  wood,  well  hooped  round 
by  iron  rings,  and  the  lower  portion  D  of  cast  iron,  and  so 
shaped  that  the  worm  may  hug  closely  to  the  sides  without 
loss  of  room,  and  the  "blowpipe"  fit  snugly  to  the  bottom. 
For  the  convenience  of  drawing  ofi"  the  spent  lyes,  there  are 
attached  a  pipe  and  cock  I.  Each  of  these  kettles,  resting 
upon  a  hollow  pile  of  circular  mason  work  M,  is  furnished 
with  a  welded  wrought-iron  worm,  which  connects  with  the 
main  feeder  at  and  serves  as  the  boiling  medium  of  the 
soap  paste.  The  steam  is  let  on  or  off",  by  opening  or  shut- 
ting the  cock  H,  and  the  waste  steam  is  conducted  through 
the  other  end  of  the  worm  X,  which  passes  upward  by  the 
side  of  its  inlet,  and  thence  out  in  any  convenient  way 


through  the  wall  of  the  laboratory.  Also  affixed  to  the 
main  feeder  is  another  pipe,  with  a  stopcock  attached,  and 
leading  immediately  downwards  to  the  bottom  of  the  kettle, 


218  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


where  it  is  affixed  to  a  circular  iron  tube,  pierced  around  its 
circumference  with  holes.  It  is  set  immediately  below  the 
worm,  and  is  called  the blowpipe,"  serving  to  give  addi- 
tional heat  occasionally  to  the  contents  of  the  kettle,  as  well 
as  to  stir  it  up  when  necessary — an  operation  more  effectually 
executed  in  this  way  than  by  a  crutch  in  the  hands  of  a 
workman.  Tlie  whole  interior  arrangement  of  the  boiling 
pan  is  seen  at  the  figure  AD,  the  worm  detached  at  K,  and 
the  "  blowpipe"  at  L.  These  kettles  are  worked  much  in 
the  same  manner  as  the  ordinary  fire  caldrons,  except  that 
they  require  less  attention.  The  charge  of  material  is  put  in 
and  melted  by  a  rush  of  steam  through  both  the  blowpipe 
and  worm,  the  cock  of  the  latter  being  shut  off  when  it  is 
necessary.  The  cock  P  serves  to  regulate  the  current  of  steam 
from  the  generator.  We  have  inserted  three  caldrons  in  our 
figure.  In  large  factories  it  is  convenient  to  have  this  num- 
ber; one,  however,  will  answer  in  a  small  laboratory,  though 
there  will  necessarily  be  a  loss  of  time  in  cleansing  it  always, 
when  the  charge  is  to  be  changed  from  yellow  to  white  soap. 
The  curbs  of  conical  form  are  preferable,  though  other  shapes 
are  used.  Some  manufacturers  dispense  with  the  iron  bot- 
toms entirely,  and  boil  in  water-tight  vats,  or  tubs,  made 
wholly  of  wooden  staves,  hooped  together  with  strong  iron 
clamps.  This  series  of  kettles  is  well  adapted  for  bleaching 
palm  oil. 

In  the  steam  series  above  described,  the  steam  is  intro- 
duced directly  into  the  material. 

But  as  it  is  desirable  for  some  soaps  to  apply  the  steam 
upon  the  outer  surface  of  the  kettle,  we  present  below  (Fig. 
18)  a  suitable  arrangement  for  that  purpose. 

A  is  the  interior  of  a  cast-iron  kettle,  surrounded  by  brick- 
work. B  is  the  outer  cast-iron  caldron,  which  should  fit  to 
the  inner  kettle  tightly,  so  as  to  prevent  any  escape  of  steam. 
D  D  is  the  tube  leading  from  the  steam  boiler,  and  convey- 
ing the  steam  to  the  kettles.  It  is  fitted  with  a  cock,  which 
is  opened  or  shut,  according  as  the  steam  is  to  be  let  on  or 
off,  for  accelerating  or  retarding  the  boiling  of  the  soap.  C  C 
is  the  tube  by  which  the  condensed  vapor  is  discharged. 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


219 


The  cock  in  this  tube  can  be  left  slightly  open  so  as  to  ope- 
rate as  a  safety-valve,  when  one  of  these  necessary  appen- 
dages is  not  fixed  to  the  apparatus.  The  tube  E  is  the  dis- 
charge-pipe of  the  caldron.  The  brick-work  F  F  is  similar 
to  that  for  other  furnaces. 


Fig.  18. 


1.1,1 


nzzi 


Hiiberfs  Appa?'atus  for  Boiling  Soap  by  Means  of  Surcharged 
Steam. — This  apparatus,  represented  in  Fig.  19,  was  patented 
by  Mr.  II.  G.  Hubert.  "A  is  a  steam  boiler  of  ordinary 
construction.  B  is  a  steam  pipe  provided  with  a  sto.pcock 
C.  D  is  a  steam  super-heater.  E  is  a  pipe  leading  from  the 
super-heater  D  to  the  receiver  F.  G  is  a  pipe  supplying  air 
from  a  force  pump.  H  is  a  valve  for  regulating  the  intro- 
duction of  air  into  the  apparatus  through  the  pipe  I.  F  is  a 
receiver,  where  the  steam  and  air  are  mixed  together.  K  is 
a  pipe  conveying  the  mixed  air  and  steam  to  any  number  of 
soap-boiling  apparatus.  L  L  are  pipes  conveying  the  steam 
and  air  to  the  bottom  of  the  vats  M  M  ;  S,  S,  S,  S,  are  radia- 
ting pipes  perforated  with  holes,  turned  in  opposite  directions, 
so  that  when  the  air  and  steam  issue  from  them,  they  will 
cause  a  rotating  motion  of  the  whole  mass  of  supernatant 
liquid  in  the  vats  MM.  R  is  the  tank  for  receiving  the  lye 
drained  by  the  cocks  P  P.  The  operation  of  this  apparatus 
is  easily  understood.   The  lye  and  fats  being  introduced  into 


220 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 
Fig.  19. 


the  vats  M  M,  steam  is  allowed  to  escape  gradually  into  the 
apparatus  D,  where  it  becomes  super-heated,  and  is  carried 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


221 


over  and  injected  through  the  mass  in  the  tanks  MM.  When 
it  is  required  that  the  mass  be  stirred,  then  air  is  introduced 
into  the  apparatus  by  turning  the  valve  H.  It  will  be 
observed  that  the  workman  has  perfect  control  of  the  opera- 
tion, being  able  by  simply  turning  the  cock  C  or  H,  to  in- 
crease or  diminisVi  the  heat,  and  to  stir  or  leave  the  pasty 
contents  of  the  vats  M  M  at  rest." 

St.  John^s  Steara  Jacket. — Tliis  apparatus  accomplishes  the 
mixing  and  boiling  of  the  soap  ingredients  simultaneously. 
As  the  steam  circulates  around  the  kettle,  and  through  tubes, 
instead  of  being  admitted  directly  into  the  paste,  a  uniform 
temperature  may  readily  be  established.  The  whole  arrange- 
ment is  shown  in  longitudinal  vertical  section,  by  Fig.  20. 
The  boiling  pan  a  a  is  enveloped  by  a  steam  casing  or  jacket 
6,  adjusted  to  which  is  a  tube  /:,  communicating  with  the 
steam  generator,  and  leading  the  steam  into  the  space  c  e, 
between  the  pan  and  outer  casing.  The  exit  pipe  t/,  with 
its  stopcock  :r,  is  for  drawing  oft'  the  condensed  steam,  as 
may  be  necessary;  and  the  safety  valve  is  a  protection 
against  excessive  pressure.  The  stirring  is  accomplished  by 
means  of  the  revolving,  horizontal  arm  d  carrying  teeth 
/"/,  and  mounted  upon  a  perpendicular  shaft  e.  The  stirring- 
apparatus  is  put  in  motion  by  suitable  gearing,  consisting  of 
the  bevel  wheel  ^,  mounted  horizontally  on  the  vertical  shaft 

and  working  into  a  similar  wheel  on  the  horizontal 
shaft  ^,  which  has  a  pulley  J  o\\  its  other  end,  driven  by  a 
band  or  strap  E.  When  the  boiling  is  completed,  the  con- 
tents of  the  kettle  or  pan  are  drawn  off'  through  the  pipe/, 
and  its  branches  m  m.  The  tubes  p  p  closed  at  their  u[)per 
ends,  and  communicating  with  the  space  between  the  pan 
and  jacket,  by  conveying  the  steam  throughout  the  con- 
tents of  the  pan  extend  the  heating  surface  of  the  latter. 
They  also  serve  the  purpose  of  stops  for  breaking  the  mass  as 
it  is  carried  around  by  the  stirrers//.  The  swivel  or  T 
joint  u  is  so  constructed  that  the  arms  m  r/i  niay  be  turned 
horizontally  in  a  circle,  so  as  to  bring  the  cocks  x  x  over  a 
range  of  receivers.  J.  is  a  cock  for  letting  the  charge  into 
the  branch  pijtes  m  m.    Another  cock,      is  for  regulating 


222  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

the  admission  of  steam  to  the  chamber  c,  and  the  tubes  j)  p. 
The  clutch  lever  n  is  for  adjusting  the  cog-wheel  h  with  the 


Fig.  20. 


cog-wheel  g,  when  the  stirrers  are  to  be  put  in  motion,  JE  is 
a  driving-band,  connected  with  the  pulley  J  on  the  shaft  i, 
F  F  are  stay  bolts  for  coupling  the  kettle  and  jacket. 

Morfifs  Steam  Jac/i:^^.— This  jacket  produces  the  same  effects 
as  the  above.  The  following  figure  represents  a  vertical 
section  of  it.  A  is  the  soap  kettle,  which  may  be  made  of 
any  shape  and  of  any  material,  having  a  waste-cock  C,  and 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


223 


mounted  upon  a  frame  B.  D  is  an  upright  shaft,  hollow- 
both  in  its  upper  and  lower  parts,  but  solid  in  the  middle. 
F  is  a  stuffing  box  in  which  the  shaft  D  runs,  and  is  pro- 
vided with  suitable  packing  and  a  circular  chamber,  so  that 


Fig.  21. 


steam  from  the  pipe  G  may  be  admitted  through  openings 
in  the  hollow  top  part  of  the  shaft  D.  The  lower  end  of  the 
shaft  D  runs  through  the  bottom  of  the  kettle  A,  fitting  suffi- 
ciently tight  to  prevent  the  soap  and  lye  from  escaping,  yet 
loose  enough  to  be  easily  turned.  Tw^o,  three,  or  four  pipes 
H,  so  bent  as  to  take  the  configuration  of  the  kettle  A,  are 
connected  at  both  ends  with  the  hollow  part  of  the  shaft  1). 
K  K  K  are  a  number  of  slats  fastened  to  the  pipes  H  H,  to 
strengthen  them,  and  at  the  same  time  to  oSer  more  resist- 
ance to  the  materials  to  be  stirred.    A  set  of  gearings  S,  and 


224 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


a  shaft  T,  mounted  on  the  heam  0,  are  so  arranged  as  to  give 
motion  to  the  shaft  D.  The  advantage  derived  i'rom  this 
arrangement  is  obvious,  as  the  steam  entering  the  pipe  D 
finds  no  other  outlet  than  the  pipes  H  H,  through  which  it 
rushes,  following  their  sinuosities,  till  it  reaches  the  bottom 
of  the  shaft  D,  where  the  condensed  water  is  drawn  off  at  E. 
The  heat  thus  conveyed  into  the  pipes  H  H,  is  communicated 
to  the  materials  contained  in  the  kettle  A,  which  being  con- 
tinually stirred,  have  the  heat  more  uniformly  distributed 
throughout  their  mass  than  could  be  effected  by  the  ordinary 
methods.  This  is  a  most  useful  kettle  for  the  extempore 
soaps. 

Caldrons  or  Boiling  Pans. — In  smaller  factories  the  old 
mode  of  boiling  soap  by  the  naked  fire  may  be  employed, 
and  we  proceed  to  give  a  description  and  drawing  of  the 
kind  of  kettles  most  advantageous  for  the  purpose.  The  size 
of  the  caldrons  should  be  proportioned  to  the  amount  of 
soap  intended  to  be  made  at  each  boiling.  The  bottom  pan 
may  be  of  cast  iron,  but  in  England  they  prefer  Swedish 
wrought-iron  plate.  This  bottom  pan  is  built  in  brick  ma- 
sonry, so  that  the  heat  acts  solely  upon  its  bottom.    Fig.  22 


Fig.  22. 


— 1 — p 

1  - 

-  1 

1  '  >  '  ^ 

1  1 

tr,  1 

1            1  i 

1 

1 

N 

1 

0000 

\\ 

-  1 

\  1  1 

I  I 

1  1 

1       i  1 

1  \ 

shows  one  of  these  caldrons.  Should  there  be  several,  they 
are  placed  on  a  line  with  each  other,  and  over  a  furnace 
beneath.  To  the  caldron  a  tube  of  about  two  inches  dia- 
meter is  adapted,  which  serves  as  an  outlet  for  the  sub-lye 
which  remains  under  the  boiled  paste.  The  furnace  is  made 
in  the  usual  manner.    The  arrangement  of  the  mason  work 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


225 


is  generally,  however,  left  to  the  skill  and  ingenuity  of 
the  bricklayer.  These  soap  pans  or  caldrons  are  cast  with 
a  flange  at  their  top,  so  that,  when  necessary,  an  adjunct 
cylinder  of  wood,  in  the  shape  of  a  cone,  may  be  fastened 
to  them.    This  is  called  the  curb.  Fig.  23,  or  upper  part 


Fis.  23. 


of  the  caldron.  It  is  nothing  more  than  a  hollow  cone 
of  iron-bound  staves,  made  to  fit  the  flange  of  the  iron  ket- 
tle. It  can  extend  as  high  as  desired,  and  is  made  of  wood, 
so  as  to  save  the  cost  of  metal,  and  the  mason  work  neces- 
sary to  inclose  it.  The  cones  stand  erect,  but  they  should 
be  strongly  and  tightly  fastened,  and  jointed  to  the  lower 
pan.  In  this  way  a  pan  may  be  enlarged  at  much  less  cost 
than  for  a  caldron  wholly  of  iron  requiring  to  be  entirely 
inclosed  within  mason  work. 

Jjye  Vats, — The  lye  vats,  in  very  extensive  factories,  are 
m.ade  of  brickwork,  smoothly  cemented  within  ;  but  much 
the  better  material  would  be  lead  ;  for  then  one  set  of  vats 
would  answer  for  all  kinds  of  soaps,  as  the  lye  prepared  in 
them,  not  being  acted  upon  by  the  metal,  wnll  be  perfectly 
clean.  Large  tuns  lined  w^ith  sheet  lead,  and  with  cullen-, 
dered  false  bottoms,  Fig.  24,  are  perhaps  the  best  and  most 
durable  fixture  of  this  kind  that  could  be  put  up.  In  this 
case  there  is  a  cock  fitted  near  the  bottom  of  each  tun,  and 
through  it  the  clear  lye  collecting  in  the  lower  part  of 


226  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


the  tun,  between  the  diaphragm  and  the  bottom,  can  be 
drawn  off  into  tubs  below  for  use,  as  may  be  wanted.  Close 


Fig.  24. 


by  these  vats  there  must  be  a  pump  or  hydrant,  with  its  out- 
let spout  conveniently  arranged  for  a  supply  of  water,  in 
quantity  as  required. 

An  excellent  substitute  for  the  cock  is  a  long-handled 
plug  of  wrought  iron.  Fig.  25.    Its  conical  tip  must  be 


Fig.  25. 


tightly  and  smoothly  wrapped  with  tow,  so  that  when  in 
use,  it  may  make  a  tight  joint.  It  is  placed  in  the  hole  from 
the  interior  of  the  vats,  so  that  being  always  in  position,  it 
is  only  necessary  to  give  the  handle  a  push  when  it  is  desired 
to  draw  off  the  lye,  and  draw  it  outwards  again  when  the 
flow  is  to  be  stopped.  In  large  establishments,  where  there 
are  a  number  of  lye  vats  in  constant  operation,  it  is  necessary 
to  have  a  tightly  covered  reservoir  for  the  reception  of  the 
lye  as  fast  as  it  runs  through ;  for  there  is  not  space  enough 
below  the  false  bottom  for  any  great  accumulation  of  liquid. 
There  are  generally  several  vats  to  each  laboratory,  but  the 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


227 


number  depends  entirely  upon  the  amount  of  soap  manu- 
factured, and  consequently  the  proportion  of  lye  necessary 
for  the  steady  prosecution  of  the  work. 

In  a  Marseilles  soap  house,  the  lye  vats  are  in  sets  of 
four.  1^0.  1  is  the  fresh  vat  which  receives  the  fresh  mix- 
ture of  alkali  and  lime ;  the  next  one,  or  ITo.  2,  being  the 
avancaire^  or  an  advanced  stage.  Ko.  3  is  the  small  avan- 
caii^e^  being  two  steps  in  advance,  and,  therefore,  contain- 
ing weaker  liquor;  and  l^o,  4  is  the  t(;«^er-v«^,  because  into 
that  the  water  is  directly  introduced.  Into  No.  3  the 
moderately  exhausted  or  somewhat  spent  lyes  are  thrown. 
From  ISTo.  3  the  lye  is  pumped  into  ISTo.  2,  to  be  strength- 
ened, and  in  like  manner  from  No.  2  into  No.  1.  Upon 
the  lime  paste,  in  No.  4,  which  has  been  taken  from  No. 
8,  water  is  poured,  and  the  lye  thus  obtained  runs  upon 
the  paste  of  No.  3,  which  has  been  taken  from  No.  2.  No. 
3  is  twice  lixiviated,  and  No.  2  once.  The  receiver  under 
No.  1  has  four  compartments,  into  No.  1  of  which  the  first 
and  strongest  lye  is  run  ;  into  No.  2,  the  second  lye  ;  into 
No.  3,  the  third  lye ;  and  into  No.  4,  the  fourth  lye,  which  is 
so  weak  as  to  be  used  instead  of  water,  for  lixiviation.  The 
lime  in  vat  No.  4,  when  exhausted,  is  emptied  out  of  the 
window  near  which  it  stands,  in  which  case  the  water  is 
poured  upon  the  contents  of  No.  3 ;  and  upon  No.  2,  the 
somewhat  spent  lyes.  No  1  is  now  the  avancaire  of  No.  4, 
because  this  has  become,  in  its  turn,  the  fresh  vat,  into  which 
the  fresh  soda  and  quicklime  are  put.  The  lye  discharged 
from  No.  3  comes  then  upon  No.  2,  and  after  having  been 
run  through  it,  is  thrown  upon  No.  1. 

In  some  factories  iron  vats  in  the  form  of  inverted  cones 
are  used,  the  outlet  for  the  lye  being  through  an  opening  at 
the  apex  of  the  cone.  Then  it  is  judicious  to  have,  also,  a 
lead-lined  vat  for  the  finer  qualities  of  soap ;  as  it  is  requisite, 
especially  for  toilet  soaps,  to  have  the  lye  perfectly  clear  and 
colorless,  and  free  from  iron. 

In  the  apartment  containing  the  lye  vats  there  should  be 
two  pieces  of  auxiliary  apparatus  for  the  preparation  of  the 
lye  materials.    These  are  a  mill  for  grinding  the  alkali  when 


228  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


lumpy ;  and  a  drum  sieve  for  thoroughly  mixing  it  with  the 
lime.    Both  are  to  be  driven  by  steam  power. 

The  siphon  should  be  of  half-inch  lead  pipe,  and  may  be 
made  after  Coffee's  pattern,  for  moderate  volumes  of  liquid, 
as  it  possesses  many  advantages  over  the  usual  forms  in 
delivering  the  liquid  without  any  inconvenience  to  the  ope- 
rator.   It  is  shown  by  Fig.  26,  and  consists  of  a  bent  tube. 


Fig.  £G. 


one  leg  of  which  is  longer  than  the  other,  and  a  smaller  late- 
ral tube  B,  capped  with  a  large,  hollow  India-rubber  ball  A. 
The  long  leg  has  also  a  stopcock  near  its  lower  end.  It  is 
put  in  operation  by  closing  the  cock,  compressing  the  bag, 
and  quickly  immersing  the  short  leg  in  the  clear  lye,  to 
within  an  inch  or  less  of  the  subsident  carbonate  of  lime,  as 
represented  in  the  drawing.  The  act  of  compressing  the  ball 
produces  diminution  of  the  elastic  force  of  the  internal  air 
by  expelling  the  most  of  it,  so  that  as  soon  as  the  hand  is 
removed  from  the  ball,  the  outward  pressure  of  the  air  drives 
the  liquid  up  to  the  highest  point  of  the  bend,  whence  it 
drops,  by  the  force  of  gravitation,  on  the  opening  of  the 
cock,  and  flows  out  in  a  continuous  stream,  as  long  as  the 
mouth  of  the  short  leg  is  covered  by  it. 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


229 


The  best  form  of  grinding  apparatus  is  Bogardus's  eccentric 
mill,  Fig.  27;  for  it  does  its  work  economically,  both  as  to 
time  and  cost;  and,  moreover,  is  not  an  expensive  machine. 
It  is  so  constr-ucted  that  "both  plates  revolve  in  the  same 
direction  (with  nearly  equal  speed)  on  centres,  are  apart 


Fig.  27. 


from  each  other  one  inch  more  or  less.  The  centre  ot 
the  one,  or  axis  thereto  affixed,  rests  and  revolves  upon  a 
stationary  point;  whilst  the  prime  mover,  by  means  of  a 
belt  or  gearing,  communicates  motion  to  the  other  plate. 
The  circles  which  are  cut  in  the  plate  act  like  revolving 
shears  by  cutting  every  way ;  and  when  the  mill  is  in  opera- 
tion, they  cause  a  peculiar  wrenching,  twisting,  and  sliding 
motion,  admirably  adapted  for  every  species  of  grinding. 
The  ground  substance  is  delivered  promptly  without  clog- 
ging the  mill." 

The  drum  sieve.  Fig.  28,  is  merely  a  wooden  framework 
cylinder  A,  covered  with  wire  gauze,  the  meshes  of  which  are 
larger  or  smaller,  according  to  the  degree  of  fineness  which  it 
is  desired  to  give  the  mixture  of  alkali  and  lime.  They  should 


230  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

not,  however,  exceed  the  eighth  of  an  inch.  It  is  mounted 
upon  uprights  B,  and  is  made  to  revolve  by  means  of  the 


Fig.  28. 


shaft  and  pulley  C.  The  shelf  D  is  an  inclined  platform  for 
the  delivery  of  the  mixture  into  tubs,  as  it  passes  from  the 
seive. 

Soap  Frames. 

This  name  is  given  to  square  reservoirs  made  of  masonry, 
iron,  or  wood,  into  which  the  soap  is  run,  when  drawn  from 
the  kettle,  in  order  that  it  may  cool. 

Frames  of  Masomry, — The  first  thing  to  do  when  building 
a  masonry  frame  is  to  carefully  level  the  ground  on  which  it 
has  to  be  established.  This  done,  a  platform  of  good  masonry 
is  constructed  on  it,  at  about  four  or  five  inches  above  the 
level  of  the  ground,  and  the  dimensions  of  which  exceed,  in 
every  direction,  from  seven  to  eight  inches  the  outside  line 
of  the  walls  of  the  frame.  To  build  the  walls,  employ  well- 
burned  and  very  smooth  bricks.  For  large  frames,  the  walls 
have  generally  from  twelve  to  fourteen  inches  of  thickness, 
their  height  varies  between  twenty-four  and  twenty-six  inches 
above  the  level  of  the  platform.  In  the  front  of  the  frame 
leave  a  lateral  opening  of  about  two  feet,  in  which  is  fixed  a 
kind  of  movable  door,  which  is  used  for  removing  the  soap 
after  its  cooling.    The  mortar  used  in  the  construction  con- 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


231 


sists  of  three  parts  weight  of  good  cement,  and  one  of  fine 
sand.  When  the  walls  are  raised  to  the  proper  height,  and 
have  stood  for  two  or  three  days,  the  joints  are  cut  down 
smooth,  and  the  walls  are  thoroughly  washed  with  a  broom. 
The  next  day  they  receive  a  perfectly  smooth  coat  of  cement, 
about  one  inch  in  thickness.  As  for  the  bottom  of  the  frame, 
a  coating  of  cement  is  applied  about  one  or  two  inches  thick ; 
and  then  sufi*ered  to  dry  for  a  few  days;  on  this  coating  of 
cement  a  floor  of  hard  bricks  is  laid;  these  bricks  are  laid 
flat,  and  well  cemented  with  mortar.  It  is  proper  to  give  a 
slight  inclination  to  the  bottom  of  the  frames  in  the  direc- 
tion of  the  door,  so  as  to  permit  the  lye  to  run  off  into  a 
small  tank,  also  built  of  masonry,  and  sunk  in  the  ground 
below  the  door  of  the  frame.  The  dimensions  of  a  frame  are 
generally  regulated  by  the  capacity  of  the  kettle  for  which 
it  is  destined.  It  has  been  ascertained  that  for  regular  and 
continued  work,  three  frames  are  required  for  the  service  of 
each  kettle,  so  as  to  have  no  interruption  in  the  different 
operations.  Frames  of  masonry  are  completely  water-proof, 
and  do  not  allow  the  escape  of  any  liquid,  when  properly 
prepared.  Good  frames  last  very  long;  they  are  used  prin- 
cipally in  the  manufacture  of  marbled  soaps;  their  employ- 
ment is  general  at  Marseilles. 

Frames  of  Iron. — These  frames  generally  have  nothing  re- 
markable in  their  construction.  They  ordinarily  have  the 
form  of  a  parallelogram;  their  dimensions  vary  according  to 
the  quantity  of  soap  to  be  run  into  them.  They  are  formed  of 
strong  iron  plates,  so  firmly  riveted  together  as  to  render  im- 
possible the  loss  of  liquid.  These  frames  have  on  one  of  their 
sides  a  vertical  opening  from  top  to  bottom,  the  width  of  which 
is  from  16  to  20  inches;  this  opening  is  closed  by  a  sheet  of 
iron  and  is  used  as  a  door  to  the  frame.  It  is  by  this  open- 
ing that  the  soap  is  taken  out  after  its  cooling.  The  con- 
struction of  these  frames  is  costly,  but  they  have  the  advan- 
tage of  being  perfectly  tight,  and  of  not  allowing  any  leakage 
of  soap  or  lye. 

They  are  of  the  same  form  as  the  wooden  frames ;  but  differ 
in  size.  The  sides  are  of  wrought-iron  plate,  and  the  remaining 


232  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


portions  of  cast  iron.  Fig.  29  presents  a  side  view,  Fig.  31  the 
bottom,  and  Fig.  30  a  top  view  of  them,  as  made  by  Poole  & 


Fig.  29. 


Hunt,  engineers  and  machinists,  Baltimore ;  and  the  clamp, 
which  fits  on  the  ends,  and  holds  them  together,  is  shown 

Fig.  30. 


by  a.  They  are  drawn  to  a  scale  of  three-eighths  of  an  inch 
to  a  foot.  Being  mounted  on  wheels,  these  frames  can  readily 

Fig.  31. 


Mmrnmrnmrnrnt  iniinimin  

be  moved  from  place  to  place.  The  good  conducting  power 
of  the  metal  promotes  the  cooling  and  solidifying  of  the 
soap  paste. 

Whitaker's  Fatent  Soap  Frame. — One  of  the  most  approved 
forms  is  that  made  by  Messrs.  Hersey  Brothers,  of  Boston, 
Mass.,  Whitaker's  Patent  Soap  Frame.    It  consists  of  two 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


233 


sides  of  plate  iron,  flanged  at  their  upper  edges,  and  strength- 
ened by  ribs  of  corrugated  plate  iron,  riveted  to  their  outer 
surface,  running  in  the  direction  of  their  length  (Fig.  32). 

Fig.  32. 


These  corrugations  prevent  the  bending  or  twisting  of  the 
side  plates,  and  the  soap  cools  into  the  exact  rectangular 
shape  of  the  frame.  The  trouble  and  expense  of  the  ordi- 
nary stays  and  supports  are  here  avoided,  as  the  frame  is  self- 
sustaining.  The  sides  are  connected  by  ends  of  two-inch 
plank,  secured  by  clamps.  The  frame  is  very  light,  easily 
managed,  and  can  be  adjusted  and  unadjusted  by  one  work- 
man almost  momentarily.  The  soap  cools  very  rapidly — 
ordinary  soap  cooling  sufliciently  to  strip  in  twenty-four 
hours  in  cold,  and  in  forty-eight  in  warm  weather. 

Frames  of  Wood. — These  frames  are  made  of  oak  or  pine. 
Those  of  oak  are  costly,  and  have  the  disadvantage  of  color- 
ing the  soap ;  the  others  do  not  present  this  inconvenience, 
and  are  to  be  preferred.  IsTearly  all  the  frames  are  constructed 
of  four  movable  parts,  which  are  made  of  boards  of  pine 
wood,  about  two  or  three  inches  thick.    To  preserve  the 


234  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

wood  from  alteration  the  inside  is  lined  with  very  thin  sheet 
iron,  fixed  to  the  wood  with  tacks  about  half  an  inch  long. 
By  this  means  these  frames  may  be  used  five  or  six  years 
without  repair.  The  floor  is  of  wood  or  brick.  When  the 
soap  is  cold  and  ready  to  be  taken  oft*,  the  sides  of  the  frames 
are  removed,  and  the  cake  of  soap  remains  standing  on  the 
bottom.  In  this  country,  frames  are  made  of  pine  Avood, 
for  light-colored  and  fine  soaps  ;  and  of  cast  iron  for  common 
yellow  soap.  The  iron  frames  need  not  exceed  half  an  inch 
in  thickness;  but  those  of  wood  should  be  made  of  two  or 
three  inch  stuff.    The  shape  is  that  of  a  parallelogram,  as 


Fig.  33. 


should  be  about  36  inches  deep,  and  smoothly  jointed,  so  that 
when  they  are  placed  on  top  of  each  other  in  piles  of  three, 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


285 


four,  or  five  (Fig.  34),  they  may  form  a  water-tight  well, 
which  will  hold  the  hot  paste  without  leaking. 

The  wooden  frames  are  lifted  off,  one  at  a  time,  and  the 
soap  remains  upon  the  movable  bottom  ready  to  be  divided 
into  bars,  as  shown  by  Fig.  33.  Fig.  84,  No.  1,  shows  the  w^ell 
of  five  frames,  ready  for  receiving  the  soap  paste.  A  single 
frame  and  the  bottom  of  the  well  are  severally  presented  in 
JSTos.  2  and  3. 

The  German  frames,  like  those  of  this  country,  are  also 
constructed  so  that  they  may  easily  be  separated  into  pieces, 
being  set  up  by  nuts  and  screws,  as  shown  in  Figs.  35  and 
36.    Their  floor  is  also  movable;  and  is  shown  in  longitudi- 


Fig.  35. 


Fiff.  36. 


nal  section  by  Fig.  37,  and  in  breadth  by  Fig.  38.  It  con- 
sists of  two  layers  of  deal  boards,  in  the  upper  of  which  are 
four  grooves,  fitting  with  the  projections  in  the  sides.  The 
tw^o  narrow  sides  are  also  supported  on  the  inside  by  cross- 


Fig.  37. 


Fig.  38. 


pieces.  All  the  sides  are  strengthened  by  supports.  When 
the  several  parts  are  put  together,  the  bolts,  screw  cut  at  the 
other  end,  have  only  to  be  inserted  through  the  projecting 
parts  of  the  longer  sides,  and  made  fast  by  the  nuts  at  the 
ends,  to  form  the  whole  into  a  solid  box.  A  cloth  spread 
over  the  bottom  prevents  any  soap  from  passing  the  holes, 
through  which  the  lye  drains  off.  A  frame  with  its  sides 
and  ends  dow^n  is  shown  by  Fig.  39.  By  the  side  of  it  is  the 
clamp  used  for  holding  the  different  parts  in  position  when 


236  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


the  frame  is  set  up.  Many,  to  prevent  the  too  rapid  cooling 
of  the  soap,  are  covered  with  a  mattress  of  soft  material  on 
the  outside,  etc. 


The  Her&ey's  Patent  Rotary  Soap  Pump  of  Hersey  Bro- 
thers, of  Boston,  combines  in  itself  more  excellences  and  is 
better  adapted  to  the  requirements  of  the  trade  than  any- 
thing of  the  kind  ever  presented,  and  there  are  now  very 
few  large  manufacturers  in  the  United  States  who  use  any 
other  appliance  for  taking  off  soap.  The  pump  may  be 
set  up  in  any  convenient  position  adjacent  to  the  kettle,  and 
not  over  ten  feet  above  the  bottom  of  the  same,  and  con- 
nected to  it  by  means  of  a  two-and-a-half-inch  iron  pipe 
tapped  through  the  iron  plate  at  a  distance  of  about  two  feet 
above  the  worm  or  coil.  Each  kettle  is  thus  connected  with 
the  pump  by  the  iron  pipes,  which  have  valves  placed  upon 
them  on  the  outside  (of  the  kettle)  so  that  any  one  of  them 
may  be  readily  pumped  off*  and  framed  without  disturbing 
the  others.  The  pipe  inside  of  the  kettle  has  a  suitable 
swing-joint  so  arranged  that  it  can  be  raised  or  lowered  at 
pleasure.  The  cuts  represent  the  pump — perspective  and  sec- 
tional. Fig.  40  represents  the  pump  complete ;  when  the 
pump  is  rotated  in  the  direction  of  the  arrow,  the  outlet 
marked  S  is  the  suction  ;  when  rotated  in  the  opposite  direc- 
tion, the  opposite  outlet  becomes  the  suction.  This  is  an 
important  feature,  as  it  enables  the  discharge  pipes  to  be 
emptied  of  their  contents  in  stopping,  by  giving  a  few  revo- 
lutions by  hand  in  the  opposite  direction.  Fig.  41  is  a  view 
of  the  interior  of  the  pump  when  the  cover  is  taken  off. 


Fig.  39. 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


287 


When  turned  in  the  direction  of  the  arrow,  the  blade  F 
sweeps  around,  drawing  the  fluid  in  at  I  and  forcing  it  out 
at  H,  the  contents  of  the  pump  being  twice  emptied  during 


Fig.  40. 


each  revolution.  The  blade  F  swings  on  a  pivot ;  the  end  F, 
when  reaching  the  point  B,  at  the  lowest  point,  gaining  the 
position  there  sliown,  and  gradually  returning  to  its  former 
position  on  completing  the  revolution.  The  fluid  is  pre- 
vented from  passing  from  one  side  to  the  other  by  the  con- 
tact of  the  cone  with  the  cover.  The  set  screw,  shown  in 
Fig.  41,  bears  against  a  step  at  the  end  of  cone,  and  keeps  the 
cone  forced  against  the  cover,  and  is  screwed  up  to  compen- 
sate for  any  wear  that  takes  place.    Fig.  42  shows  the  cone 


Fig.  41.  Fir.  42. 


and  blade,  and  forms  the  entire  working  part  of  the  pump; 
no  valve  being  used,  there  is  no  chance  of  any  derangement 


238 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


in  the  operation  of  the  pump  By  means  of  the  pump  the 
soap  can  be  forced  any  distance  or  lieight.  The  soap  can  be 
pumped  from  one  kettle  into  another,  which  is  a  special  ad- 
vantage when  it  is  necessary  to  transfer  the  nigre,"  either 
in  the  state  of  a  soft  curd,  or  in  the  unseparated  state  into 
another  kettle,  to  make  room  for  a  fresh  boiling  with  clean 
stock,  and  thereby  keep  up  a  uniform  quality  of  first-class 
soap.  By  lowering  the  pipe  attached  to  the  swing-joint  in- 
side of  the  kettle,  the  lye  of  the  strengthening  change"  can 
be  pumped  from  the  very  lowest  point  in  the  bottom  of  the 
kettle,  Avhile  still  hot,  into  another  in  which  stock  is  being 
saponified,  thereby  economizing  steam.  In  certain  cases 
where  it  is  undesirable  to  pump  the  lye  over  the  curb  into 
the  kettle,  because  of  the  froth  which  it  may  occasion,  an- 
other plan  can  be  adopted,  which  admirably  brings  into  play 
the  whole  system  of  pump,  valves,  and  swing-joints  of  the 
two  kettles,  from  the  bottom  of  one  of  which  it  is  required 
to  pump  the  hot  lye,  and  force  it  through  the  iron  piping 
down  to  the  bottom  of  the  other.  Lye  of  any  kind,  whether 
spent  lye,  or  strengthening  change  lye,  strong  caustic  lye, 
either  hot  or  cold,  grease  or  thick  oil  can  be  easily  and  quickly 
pumped  by  this  pump.  The  pump  is  10  inches  in  diameter 
and  2J  inches  in  outlet,  revolutions  120  per  minute,  Capacity 
6000  gallons  per  hour. 

Cutting  Operation. — When  the  soap  sets  firmly,  the  frames, 
according  to  their  construction,  are  either  lifted  off  or  un- 
bound, by  loosening  the  clamps,  and  removed,  so  as  to  leave 
resting  on  the  bottom  a  solid  mass  of  soap,  corresponding  in 
size  with  the  interior  of  the  wells,  as  shown  in  Fig.  38.  It 
is  then  divisioned  oft' on  the  sides  by  means  of  a  scribe,  Fig. 
43,  which  is  a  wooden  slat,  carrying  on  its  smooth  side  a 
number  of  slender  iron  teeth.  The  workman,  then  taking  a 
brass  wire,  Fig.  44,  directs  it  in  the  track  of  the  teeth,  and 
thus  cuts  oft*  one  slab  of  the  pre-arranged  thickness,  as 
shown  by  Fig.  45.  When  the  whole  block  is  thus  divided 
into  slabs,  the  latter  are  in  their  turn  reduced  to  bars  and 
lumps  of  smaller  dimensions,  the  usual  size  of  the  bars  being 
12  to  14  inches  long,  by  3  inches  every  other  way.  The 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY.  239 


pound  lumps  are  about  5  or  6  inches  long,  3  inches  deep,  and 
the  same  width.    The  size  of  the  slabs  must,  therefore,  be 


Fig.  43.  Fig.  44. 


regulated  accordingly  ;  and,  therefore,  it  is  convenient  to 
have  a  scribe  with  several  sets  of  teeth,  as  shown  in  Fig.  33. 


Fig.  45. 


Such  an  instrument  is  used  in  the  factories,  and  is  nothing 
more  than  a  piece  of  hard  ^vood,  about  two  inches  square, 
with  each  of  its  four  sides  smoothly  planed,  and  bearing 
slender  teeth.  On  one  side  they  may  be  set  1  inch  apart 
from  each  other;  on  the  second,  2  inches;  on  the  third,  2J 
inches ;  and  on  the  fourth,  3 J  inches;  care  being  taken,  how- 
ever, that  the  distance  between  the  teeth  of  the  respective 
sides  is  uniform.  In  this  manner,  slabs  and  bars  may  be 
smoothly  and  accurately  cut,  according  to  the  size  traced  out 
upon  the  block  by  the  teeth  of  the  scribe. 

A  much  more  rapid  method  of  dividing  the  blocks  into 
bars,  is  that  invented  by  Yan  Haagen,  of  Cincinnati,  and 
which  requires  the  use  of  two  pieces  of  machinery,  as  shown 
by  Figs.  46  and  47.    The  first  is  called  the  slabbing  and  bar- 


24:0  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

ring  machine^  and  consists  of  a  carriage  A,  which  is  so 
grooved  at  the  top  as  to  allow  the  wires  to  pass  entirely 
through  the  block  of  soap.  This  carriage  is  then  moved 
back  to  the  driver  B,  and  on  it  is  placed  a  whole  block  of 
soap  as  it  comes  from  the  frame.    This  is  done  by  a  peculiar 


Fig.  46. 


truck,  as  shown  in  diagram  ]^o.  46,  made  and  constructed 
expressly  for  the  purpose.  The  block  of  soap  having  been 
first  cut  loose  from  the  bottom  of  the  frame;  this  truck  is 
run  to  the  side  of  it,  and,  means  of  rack  and  pinions 
worked  with  a  lever,  the  block  of  soap  is  slipped  on  .  the 
truck,  brought  to  the  machine,  and,  by  the  same  power,  there- 
upon placed.  All  this  is  done  with  great  ease  and  despatch, 
and  by  the  same  power. 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


241 


The  range  of  wires  C  is  regulated  by  corresponding  gauges 
in  the  upright  posts,  which  allow  it  to  be  set  to  cut  slabs  of 
any  desired  thickness.  The  block  of  soap  is  forced  up  to 
those  wires  by  the  driver  B,  propelled  by  means  of  racks  and 
pinions  and  a  winch.  It  will  be  seen  that  in  this  way  the 
block  will  be  converted  into  slabs.  There  is  a  similar  hori- 
zontal arrangement  of  cutting-wires  D,  and  confined  to  a 
vertical  motion  by  the  posts  of  the  frame.  These  wires  are 
also  arranged  as  above,  so  that  any  desired  bars  may  be  cut. 
It  is  caused  to  descend  by  the  action  of  the  rack  and  pinions 
and  winch  as  above;  and  with  this  part  of  the  machine  the 
slabs  are  converted  into  bars  without  handling  the  same. 
They,  consequently,  are  much  neater  and  smoother  than  they 
could  be  cut  otherwise. 

The  wires,  being  fastened  at  one  end  to  a  spring  E  E,  will 
easily  yield  and  form  the  required  loops  at  the  beginning  of 


Fig.  47. 


the  operation;  and  then  both  ends  become  fixed,  so  that  the 
loops  cannot  get  any  larger,  if  the  soap  be  very  hard ;  in 
which  case  the  long  loop  is  more  apt  to  warp  and  cut  uneven. 
The  steady  motion  of  this  machine  permits  the  use  of  much 
16 


242  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

smaller  wire  than  will  do  for  hand-cutting,  and  consequently 
the  work  is  much  smoother.  This  apparatus  cuts  the  blocks 
of  soap  into  bars  as  long  as  its  width.  To  make  pound  lumps 
or  small  cakes  and  tablets,  the  slabs  must  be  transferred  to 
the  second,  or  caking  machine^  Fig.  47. 

The  slabs  are  placed  in  as  great  number  as  can  be  got  on, 
upon  a  range  of  rollers  A,  and  forced  through  the  range  of 
wires  B,  by  the  driver  C,  which  is  propelled  by  racks  and 
pinions  and  a  crank.  The  soap  having  been  forced  through 
lengthwise,  and  the  crank  being  shifted,  it  is  then  forced 
through  the  range  of  wires  D,  by  the  driver  E.  Both  the 
drivers  are  connected  with  the  same  crank,  and,  by  displac- 
ing it  from  the  one,  it  gears  itself  into  the  other.   The  wires 


Fig.  48. 


Champion  soap  slabber. 


are  arranged  in  the  same  manner  as  in  the  slabbing  machine. 
They  may  be  readily  shifted  so  as  to  cut  any  desired  shape 
or  size. 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


243 


This  mode  of  cutting  gives  great  smoothness  and  uniform- 
ity of  weight  and  size  to  the  bars  and  lumps,  saves  handling, 
scratching,  and  bending,  and  effects  a  larger  gain  over  the 
usual  method,  in  time,  labor,  and  expense. 

Two  of  the  most  recently  invented  machines  for  cutting 
soap  are  those  made  by  Hersey  Brothers,  of  Boston,  Mass., 
and  here  illustrated  by  Figs.  48  and  49. 

Ihe  Champion  Slabber  (Fig.  48)  is  similar  to  that  of  Van 
Hagen,  already  described,  with  some  improvements  that 
make  it  more  rapid  in  its  working.  Ealston's  cutter  (Fig. 
49)  has  an  attachment  for  spreading  and  stamping,  so  that 
the  cakes  are  furnished  ready  for  packing ;  it  is  simple  and 
fast  in  action,  and  large  quantities  of  soap  can  be  cut  and 
stamped  in  a  working  day. 


Fig.  49. 


Ralston's  patent  cutter  with  stamping  and  spreading  attachments. 


Grutching  Machines.  Stephen  Strum's  Soap-erutching  ma 
chine,  also  made  by  Hersey  Brothers.  (See  Figs.  50  and  51.) 
This  machine  is  simple  in  construction,  and  perfect  in  its 
action.  It  crutches  the  soap  completely  within  three  minutes, 


244 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


and  gives  it  a  smoothness  and  transparency  which  can  never 
be  obtained  by  any  other  machine.    Size,  1200  pounds. 

The  speed  of  main  shaft,  with  the  working  paddles  on, 
should  be  forty-five  to  fifty  revolutions  per  minute,  and 
should  turn  so  as  to  work  the  soap  to  the  valve  and  pump  it 
out.  When  the  machine  is  charged,  the  soap  should  cover 
the  paddles  two  inches  before  the  machine  is  started.  When 
running  the  soap  into  the  frame,  the  machine  should  be 
stopped  until  the  soap  commences  to  run  slowly,  otherwise 
it  will  force  it  out  too  rapidly.  Very  little  power  is  neces- 
sary for  this  machine.    To  clean  the  machine,  put  in  four 


Fig.  50. 


Strunz's  Crutching  Machine  (outside  view) . 


or  five  bucketsful  of  boiling  salt  water  about  22  degrees 
strong,  and  run  the  machine  three  to  four  minutes;  which 
should  be  done  while  the  soap  remaining  in  the  machine  is 
warm.    The  machine  must  always  be  cleaned  after  using. 


THE  ESTABLISHMENT  OF  A  SOAP  FACTORY. 


245 


Fig.  51. 


Strunz's  Crutching  Machine  (working  part  of  machine). 


The  Jacket  Crutching  Machine  (Fig.  52). — The  jacket  on  this 
machine  is  a  circulating  one,  and  is  said  to  have  no  equal  in 
its  rapid  heating  or  cooling  power.  There  is  no  dead  point 
in  the  jacket  as  in  other  jackets  where  the  warm  water  re- 
mains for  a  long  time  outside  of  the  current.  The  drawing 
shows  two  pipes  on  one  side;  one  is  to  be  connected  with 
steam  and  the  other  with  water.  The  escape  should  be  left 
always  free,  and  no  cock  or  valve  should  be  on  the  escape 
pipe.  The  little  cock  on  the  bottom  is  to  let  the  water  out 
of  the  jacket  to  prevent  it  from  freezing,  or  else  the  jacket 
would  burst.  The  steam  should  never  be  let  on  unless  the 
jacket  is  free  from  water,  otherwise  it  may  strain  the  machine. 
These  crutching  machines  are  very  useful  for  mixing  the 
colors  and  perfumes  of  toilet  soaps. 

We  have  now  left  little  to  add  to  the  needed  implements 
except  the  minor  ones,  as  hand  stirrers,  or  paddles  and  crutches, 
which  are  too  well  known  to  need  description,  scales,  weights, 
shovels,  and  spades  for  cutting  out  tallow,  etc. 


246 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Almost  all  soaps  are  now  stamped,  and  many  wrapped ; 
for  stamping  there  are  numerous  presses  in  use,  the  most  im- 
portant have  a  full  description  in  our  chapter  on  toilet  soaps. 

Fig.  53. 


Strunz's  Jacket  Crutehing  Machine. 


Minor  Implements. — The  minor  implements  of  the  soap 
laboratory  are,  a  crutch,  Fig.  53,  composed  of  a  long  wooden 

Fig.  53. 


1^ 


□ 


handle  adjusted  at  the  end  to  a  board,  and  used  for  stirring 
the  soap  paste  in  the  operation  of  "  mottling  large,  cullen- 
dered,  iron  ladles,  with  long,  wooden  handles  (Fig.  54)  for 


THE  ESTABLISHMENT  OP  A  SOAP  FACTORY.  247 

dipping  out  the  hot  paste  from  the  kettles,  and  copper 
buckets  (Fig.  55)  for  conveying  it  to  the  frames. 


Fig.  54.  Fig.  55. 


Copper  dippers,  with  handles  of  two  or  more  feet  in  length, 
Fig.  56,  are  used  for  dipping  the  soap  into  frames  and  for 
many  other  purposes. 


Fig.  56. 


248 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


SECTIOJS"  XI. 

THE  FABRICATION  OF  SOAPS. 

Soaps  by  Boiling. — The  suitable  preparation  of  the  lyes  for 
the  decomposition  of  the  fatty  bodies  is  beyond  doubt  the 
most  important  process  in  the  art  of  making  soap,  and  it 
therefore  requires  the  closest  attention  and  study,  for  with- 
out the  knowledge  and  experience  this  study  gives,  much 
loss  of  time  and  material  may  result. 

We  here  repeat  that  the  alkalies  of  commerce  are  never 
pure,  and  in  our  previous  sections  we  have  described  these 
impurities  and  the  modes  of  analysis.  We  will  now  give 
instructions  for  the  proper  preparation  of  the  lyes  for  use, 
with  suitable  tests  for  strength  and  purity.  For  ordinary 
purposes  the  caustic  lyes  of  soda  as  now  received  are  gene- 
rally of  sufficient  purity  when  freshly  prepared  for  making 
common  soaps,  though  there  are  none  of  them  that  do  not 
require  an  investigation  before  entire  confidence  can  be  given 
to  them.  With  potash  the  soap-maker  will  find  still  more 
difficulty  as  it  is  usually  still  more  impure,  as  has  also  been 
shown,  though  in  making  soft  soap  with  the  potash  lyes  the 
process  is  quite  different  from  that  in  use  for  the  hard  soaps 
from  soda  lyes.  Yet  a  pure  and  caustic  alkali  is  essential  to 
nearly  all  methods.  Whether  we  need  a  potash  or  a  soda 
lye  it  is  necessary  in  almost  all  cases  to  render  them  caustic, 
that  is,  to  remove  their  carbonic  acid  by  means  of  lime,  and 
this  lime  should  be  reliable  and  be  tested  to  discover  if  it 
contains  any  impurities  or  at  least  such  an  excess  of  them  as 
to  make  it  unfit  for  use.  These  tests  are  also  shown  else- 
where. The  action  of  the  lime  is  to  remove  the  carbonic  acid, 
by  the  power  it  has  of  great  affinity  for  that  acid,  causing  a 
decomposition  by  absorbing  it  and  forming  an  insoluble  car- 
bonate of  lime  which  is  precipitated,  after  giving  a  greater 
part  of  its  oxide  to  the  alkali. 


THE  FABRICATION  OF  SOAPS. 


249 


Of  the  quantity  of  hydrate  of  lime  necessary  to  make  caus- 
tic a  given  quantity  of  alkali,  there  is  great  diversity  of 
opinion,  yet  there  is  a  rule  which  must  be  studied,  for  an 
alkali  may  work  wrong  that  has  too  little  or  too  much  lime, 
or,  as  is  technically  called,  too  low  or  too  high  in  lime.  Thus 
it  is  necessary  to  give  due  regard  to  the  properties  of  lime  and 
to  its  action  in  strong  or  weak  lyes  which  is  quite  differ- 
ent, as  lime  will  not  act  in  strong  solutions  of  alkali. 

We  have  heretofore  given  the  proper  instructions  for  the 
alkalimetric  tests  for  these  materials,  and  they  should  re- 
ceive attention  to  aid  the  necessary  calculations,  yet  we  will 
give  an  example  as  a  further  guide. 

The  carbonate  of  potash  is  a  combination  of  1  equivalent 
potash  =  47.11,  and  1  equivalent  carbonic  acid  =  22,  and  its 
equivalent  is  therefore  69.11.  If  we  desire  to  change  this 
into  caustic  alkali,  we  must  extract  the  carbonic  acid.  This 
is  done  by  offering  an  equivalent  of  caustic  lime,  which,  when 
changed  into  carbonate  of  lime,  will  absorb  likewise  1  equi- 
valent of  carbonic  acid.  Since,  however,  the  equivalent  of 
the  caustic  lime  is  =  28,  it  follows  that  to  69.11  parts  in 
weight  of  carbonate  of  potash  28  parts  in  weight  of  caustic 
lime  must  be  applied,  to  make  the  former  completely  caustic. 
To  50  kilog.  (110  lbs.)  of  pure  carbonate  of  potash,  therefore, 
20.3  kilog.  (44.66  lbs.)  of  caustic  lime  are  added. 

We,  however,  have  never  to  do  with  pure  carbonates  of 
the  alkalies,  nor  with  pure  caustic  lime,  so  that  in  practice 
other  corresponding  proportions  are  required  than  are  just 
given  by  theoretical  calculation.  Supposing,  for  instance, 
the  potash  for  preparing  the  caustic  lye  contains  72  per  cent, 
of  carbonate  of  potash  and  the  lime  contains  82  per  cent, 
pure  caustic  lime,  then  we  must  in  the  same  ratio,  as  the 
potash  contains  less  than  100  per  cent., take  less  lime;  while 
in  the  same  proportion  as  the  burned  lime  contained  less 
caustic  lime,  apply  more  of  the  lime.  In  the  suggested  ex- 
ample the  calculation  would  be  rendered  thus:  X(that  is 

40  6  X  72 

the  necessary  quantity  of  lime)  =  — '- —         =  35.65  ;  that 

82 

is,  we  would  apply  100  kilog.  (220  lbs.)  of  a  72  per  cent,  potash 


250  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


35.65  kilo^.  (78.43  lbs.)  of  slaked  lime  of  82  per  cent,  pure 
caustic  lime  in  order  to  obtain  a  perfect  caustic  lye. 

The  pure  carbonate  of  soda  contains  also  to  1  equivalent 
=  31.0  parts  soda,  1  equivalent  =  22  parts  carbonic  acid,  and 
for  its  separation  again  1  equivalent  lime  =  28.0  parts  would 
become  requisite.  100  kilog.  (2::0  lbs.)  of  pure  carbonate  of 
soda  require,  therefore,  for  its  change  into  caustic  soda  52.83 
kilog.  (116.23  lbs.)  of  pure  caustic  lime.  The  weaker  a  soda 
is  the  less  lime,  and  the  more  inferior  the  lime,  the  more 
is  to  be  used  in  order  to  make  a  certain  quantity  of  soda 
caustic.  The  following  calculation  is  exactly  the  same  as 
under  the  same  proportion  of  the  potash.  Supposing  we 
have  a  soda  of  92  per  cent,  and  a  lime  of  80  per  cent.,  we 

have  the  following  equation  :  X  =  ^^-^^  ^ 


80 


where  X 


again  represents  the  necessary  amount  of  lime,  and  thus  is 
found  60.76  kilog.  (133.67  lbs.). 

According  to  this  the  tables  below  are  calculated ;  they 
contain  the  respective  changeable  quantities  of  the  lime  to 
be  applied  in  proportion  to  the  contents  of  potash  and  soda 
to  pure  carbonate  of  alkali,  and  the  contents  of  the  pure 
slaked  lime,  each  from  5  to  7  per  cent.  This  is  for  practice 
sufficiently  accurate ;  meanwhile  the  tables  may  be  easily 
changed  if  other  proportions  occur  by  means  of  interpola- 
tions. 

I.  Table  for  Potash, 


Of  lime  if  the  same  contains 


degree  require 

90 

85 

80 

75 

70 

65 

60 

55 

50 

100  per  cent,  potash, 

45.11 

47.77 

50.75 

54.01 

58.00 

62.46 

67.67 

73.82 

81.20 

95      "  " 

42.86 

45.38 

48.21 

51.43 

55.10 

59.34 

64.28 

70.12 

77.12 

90      "  " 

40.60 

42.99 

45.67 

48.96 

52.20 

56.22 

60.90 

66.44 

73.08 

85      "  " 

38.35 

40.60 

43.14 

46.01 

49.30 

53.15 

57.52 

62.75 

69.01 

80      "  " 

36.09 

38.21 

40.60 

43.31 

46.40 

49.97 

54.13 

59.06 

64.96 

75      "  " 

33.83 

35.82 

38.06 

40.60 

43.50 

46.85 

50.75 

55.36 

60.90 

70      "  " 

31.58 

33.44 

35.53 

37.90 

40.60 

43.74 

47.37 

51.68 

56.84 

65      "  " 

29.32 

31.05 

33.00 

35.19 

37.70 

40.60 

43.98 

48.00 

52.78 

60      "  " 

27.06 

28.66 

30.47 

32.48 

34.80 

37.48 

40.60 

44.31 

48.72 

55      "  " 

24.81 

26.27 

27.92 

29.77 

31.90 

34.36 

37.22 

40.60 

44.66 

50  " 

22.56 

23.88 

25.37 

27.06 

29.00 

31.23 

38.83 

36.91 

40.60 

THE  FABRICATION  OF  SOAPS.  251 


IL  Table  for  Soda. 


100  kg.  soda  of  appended 
degree  require 

Of  lime  if  the  same  contains 

90 

65 

SO. 

75 

70 

65 

60 

55 

50 

100 

per  cent,  soda, 

58.70 

62.18 

66.21 

70.44 

75.47 

81.28 

88.05 

96.06 

105.66 

95 

55.7  7 

59.02 

62.93 

66.91 

71.70 

77.21 

83.64 

91.25 

100.38 

90 

52.83 

55.93 

59.43 

63.40 

67.92 

73.15 

79.24 

86.45 

95.10 

85 

u  u 

49.90 

52.83 

56.13 

59.88 

64.15 

69.10 

74.84 

81.65 

89.81 

80 

u  u 

46.73 

49.72 

52.83 

56.35 

60.37 

65.02 

70.44 

76.84 

84.53 

75 

44.02 

46.61 

49.52 

52.83 

56.60 

60.95 

66.03 

72.04 

79.24 

70 

41.09 

43.51 

46.25 

49.30 

52.83 

56.89 

61.63 

67.24 

73.96 

65 

u  u 

38.15 

40.41 

42.92 

45.78 

49.05 

52.83 

57,23 

62.42 

68.68 

60 

u  u 

35.22 

37.20 

39.62 

42.26 

45.29 

48.77 

52.83 

57.26 

63.39 

55 

u  u 

32.28 

34.30 

36.32 

38.67 

41.51 

44.70 

48.42 

52.83 

58.11 

50 

u  u 

29.35 

31.07 

33.02 

35.22 

37.73 

40.64 

44.03 

48.03 

52.83 

"While  we  insist  on  the  maintenance  of  the  proper  propor- 
tions between  the  carbonate  of  alkali  and  the  lime,  we  do 
not  merely  look  to  a  saving  of  the  latter,  because  the  slaked 
lime  can  be  had  cheaply  everywhere,  so  that  the  greatest 
overplus  of  lime  will  not  influence  the  expense  of  making 
caustic  lyes.  The  advantage  of  accurately  maintaining  the 
equivalent  proportion  of  the  materials  which  come  into  con- 
sideration, rests  on  the  fact  that  a  carbonate  of  lime  is  ob- 
tained, which  may  be  lixiviated  with  the  greatest  ease  so 
that  not  only  is  time  saved,  but  also  nearly  all  the  alkali  is 
recovered,  without  being  compelled,  in  order  to  reach  the 
same  object,  to  be  overburdened  with  a  mass  of  weak  lyes, 
as  their  storage  often  occasions  more  inconvenience  than  the 
alkali  contained  therein  is  worth. 

Of  scarcely  less  importance  for  preparing  pure  lyes  is  the 
proportion  between  them  and  the  water  necessary  for  solu- 
tion. In  this  respect  the  carbonate  of  alkalies  seems  not  to 
be  proportionately  equal,  since,  according  to  the  experiments 
of  Liebig,  carbonate  of  potash  to  become  perfectly  caustic 
must  be  dissolved  in  at  least  twelve  times  its  weight  of  water, 
while  for  carbonates  of  soda  (anhydrous)  about  seven  times  the 
amount  of  water  is  required.  We  have,  however,  for  finding 
out  this  proportion  made  some  experiments,  and  found  that 


252 


TECHNICAL  TREATISE  ON  SOAP   AND  CANDLES. 


carbonate  of  soda,  even  if  dissolved  in  thirteen  times  its 
weight  of  water  and  boiled  with  a  small  overplus  of  lime, 
does  not  yet  impart  all  its  carbonate  to  the  lime.  The  fol- 
lowing are  the  results  of  these  experiments: — 

By  1  part  anhydrous  carbonate  of  soda  and  5.8  parts 

water,  remain  undecomposed  ....  15.62  p.  c.  NaO.COa. 
"  1  part  anhydrous  carb.  of  soda  and  8.2  parts  water   8.78    "  " 

"  "  "  "    13.3        "  1.29    "  " 

Even  by  the  application  of  thirteen  and  one-third  parts  its 
weight  of  water  to  that  of  carbonate  of  soda,  and  the  re- 
quired amount  of  lime,  there  were  1.29  per  cent,  remaining 
undecomposed  ;  it  also  made  but  a  trifling  difference  when  a 
larger  overplus  of  lime  was  applied.  Since  it  is  known  by 
experience  that  lyes  which  contain  9  per  cent,  of  their  con- 
tents in  carbonate  of  soda  will  saponify  the  neutral  fats, 
those  who  deem  this  an  advantage,  may  dissolve  the  soda  in 
eight  or  nine  parts  its  weight  of  water,  and  then  add  the 
necessary  quantity  of  lime  and  boil  it.  Meanwhile  the  solu- 
tion becomes  somewhat  weaker  by  changing  the  lime  into 
hydrate  of  lime,  which  imparts  its  water  to  the  lye,  because 
the  carbonate  of  lime  retains  no  water.  To  acquire  a  per- 
fectly free  carbonic  acid  lye,  we  would,  according  to  the  above 
experiments,  probably  have  to  apply  fifteen  times  the  amount 
of  water  of  the  weight  of  the  pure  carbonate  of  soda,  and 
obtain  hence  a  lye  of  3.9  per  cent,  caustic  soda,  which,  of 
course,  is  tolerably  weak.  But  a  lye  of  from  5  to  7  per  cent, 
is  in  most  cases  suitable,  i.  e.,  such  as  is  obtained  by  dissolv- 
ing carbonate  of  soda  in  ten  times  its  weight  of  water. 

For  pure  carbonate  of  potash,  the  same  proportion  must 
be  used,  and  a  lye  is  thus  obtained  of  nearly  7  per  cent,  caustic 
potash.  By  these  calculations  it  is  self-evident,  that  we 
should  only  consider  the  contents  of  pure  carbonate  of  alkali, 
so  that  for  instance  50  kilogrammes  (110  lbs.)  of  a  potash, 
which  contain  but  65  per  cent,  pure  carbonate  of  potash,  we 
dissolve  in  325  kilogrammes  (715  lbs.)  of  water,  and  a  soda  of 
35  per  cent,  pure  carbonate  of  soda  in  425  kilogrammes  (935 
lbs.)  of  water. 


THE  FABRICATION  OF  SOAPS. 


253 


After  having  in  this  manner  made  the  solution,  and  having 
brought  the  entire  quantity  to  a  boil,  we  begin  with  the  addi- 
tion of  the  previously  weighed  and  slaked  lime  (milk  of  lime) 
in  gradual  portions,  while  the  liquids  are  kept  slowly  boil- 
ing, and  continue  thus  for  a  short  time,  after  having  added 
the  last  portion  of  lime.  By  this  operation  the  lime  which 
at  first  was  of  a  gelatinous  consistency  is  changed  into  the 
crystalline  or  grainy  state,  and  may  then  be  lixiviated  with 
the  o^reatest  ease.  When  the  boilinof  has  lasted  about  half 
an  hour,  the  fire  is  removed,  when  the  carbonate  of  lime  will 
soon  settle  on  the  bottom  and  the  finished  lye  stand  clear 
above  it.  After  having  cooled  ofl:' so  far,  that  the  finger  may 
be  placed  in  it  without  scalding,  the  drawing  ofl:'  is  com- 
menced. This  is  best  performed  by  means  of  a  copper  siphon, 
or  in  place  of  such  by  one  made  of  tin-plate.  The  siphon  is 
filled  with  water  and  boths  ends  are  closed  with  the  thumbs 
of  both  hands,  which  as  they  have  to  come  into  contact  with 
the  lye  are  previously  rubbed  with  fat,  or  still  better  with 
parafiine.  The  residue,  the  carbonate  of  lime,  is  carried  into 
the  filtering  apparatus,  which  has  a  sieve  bottom,  covered 
with  coarse  canvas,  or  cotton  cloth,  in  such  a  way  that  none 
can  escape  spreading,  the  pulpy  mass  as  evenly  as  pos- 
sible thereon,  to  allow  of  a  complete  filtration,  and  fill  the 
sjtace  above  it  with  pure  water,  until  it  forms  a  layer  equally 
as  high  as  the  carbonate  of  lime,  and  filters  completely.  If 
the  necessary  care  and  attention  have  in  every  particular 
been  given,  the  lixiviation  may  be  considered  as  finished, 
and  the  lime  exhausted;  but  for  a  second  time  pure  water 
may  be  poured  upon  the  lime,  and  this  very  Aveak  lye  may 
be  used  for  preparing  the  lye  in  the  next  operation. 

Preparing  Potash  Lye  from  Wood-ashes. — Where  there  ia 
opportunity  to  purchase  large  quantities  of  good  wood-ashes 
cheaply,  their  use  offers,  for  the  preparation  of  potash-lye, 
immense  economical  advantages  over  the  use  of  potash. 

The  manipulation  is  somewhat  different  from  that  of 
potash.  After  having,  in  the  manner  heretofore  described, 
ascertained  the  contents  of  carbonate  of  alkali  of  the  wood- 
ashes,  the  required  amount  of  lime  is  calculated  that  is 


254  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


necessary  to  change  it  into  caustic  potash.  The  lime  is  slaked 
to  powder  and  mixed  with  the  wood-ashes  as  thoroughly  as 
possible.  This  mixture  is  placed  in  a  wooden,  or  still  better 
in  an  iron  vat,  in  which  is  inserted  a  sieve  bottom  covered 
with  straw,  now  adding  sufficient  water  to  it  so  that  a 
thick  paste  is  formed  which  is  left  at  rest  for  24  hours. 
It  must  be  observed  that  the  layer  is  everywhere  of  equal 
height,  and  no  gutters  are  formed,  through  which  the  water 
might  flow  off  without  having  previously  absorbed  the 
caustic  potash.  'Now  pour  water  into  the  yet  empty  part  of 
the  vat  and  permit  the  lye  to  draw  off.  The  space  between 
the  blind  and  the  real  bottom  must  have  an  opening  imme- 
diately under  the  former,  so  that  the  air  can  escape.  The 
lye  which  collects  between  the  two  bottoms  is  drawn  off  by 
means  of  a  stopcock,  and  carried  to  a  second  vat,  which  is 
prepared  in  the  same  manner  as  the  first.  It  may  also  be 
passed  into  a  third  vat,  but  in  every  case  the  quantity  of 
water  must  be  so  proportioned,  that  only  lyes  of  7  per  cent, 
caustic  potash  are  produced.  Of  this  strength,  the  lyes  may 
be  used  for  saponification  of  the  fats;  but  they  contain  as  a 
rule  such  large  amounts  of  sulphate  of  potash  and  chlorate 
of  potash  that  muddy  soft  soaps  would  be  obtained.  It  is 
therefore  necessary  to  condense  them  to  22  to  25°  B.,  when 
after  cooling  off  the  greater  part  of  these  foreign  salts  crystal- 
lize. For  use  the  lyes  are  again  diluted  with  water  till  they 
reach  the  desired  strength. 

Preservation  of  the  Lyes. — Although  it  is  not  common  to 
prepare  large  quantities  of  lyes  in  advance  and  to  preserve 
them  for  a  longer  period,  yet  it  may  be  advantageous  under 
certain  circumstances,  especially  if  the  necessary  vessels  are 
at  hand,  to  lay  up  a  supply  of  caustic  lyes;  to  avoid  the 
absorption  of  carbonic  acid,  and  to  lose  thereby  more  or  less 
of  their  efficacy.  Strictly  hermetically  tight  vessels  would 
be  necessary,  the  constructing  and  acquiring  of  which  would 
not  only  be  very  expensive  but  also  difficult.  We  have  in 
order  to  reach  this  end  used  paraffine,  of  which  we  have  caused 
to  be  thrown  according  to  the  size  of  the  vessel  a  sufficient 
quantity  upon  the  yet  warm  lye.   The  paraffine  melts,  spreads 


THE  FABRICATION  OP  SOAPS. 


255 


upon  the  lye  and  forms  upon  it  a  cover,  which  completely 
shuts  out  the  carbonic  acid.  For  this  no  special  vessels  are 
needed,  find  it  may  be  placed  in  tanks  or  in  the  so  called 
pits; — as  thereby  the  paratRne  is  in  no  wise  changed,  we  can 
always  make  renewed  use  of  it. 

In  testing  the  strength  of  lyes,  formerl}^  an  egg  was  used — 
and  in  many  instances  this  is  yet  done — for  the  approximate 
estimation,  whether  a  lye  possessed  the  necessary  strength  for 
the  paste  or  preliminary  operation,  the  lye  had  to  attain  such 
a  density  that  a  hen's  egg  would  float  upon  it.  At  a  more 
progressive  period  hydrometers  were  used  for  this  purpose  and 
are  yet  frequently  applied.  There  is  no  doubt  that  the  latter 
instrument  would  show  with  suflicient  accuracy  the  quantity 
of  alkali  dissolved  in  the  water  if  for  the  production  of  lyes 
pure  carbonate  alkalies  were  used.  But  as  such  is  not  the 
case,  and  the  potash  as  well  as  the  soda  contains  larger  or 
smaller  quantities  of  foreign  salts,  soluble  in  water,  this 
method  of  testing,  based  upon  the  specific  gravity,  can  never 
furnish  positive  results,  and  there  may  be  lyes  which  al- 
though they  prove  themselves  high  on  the  scale  of  an  hydro- 
meter, yet  may  be  proportionately  weak  in  caustic  alkali. 

On  the  other  hand,  the  alkalimetric  test  offers  the  most 
perfect  security,  and  the  modus  operandi  is  similar,  as  we 
have  already  related,  in  the  case  of  testing  potash  and  soda. 
The  main  thing  is,  that  a  correct  testing  acid  be  provided, 
and  it  would  be  best  to  prepare  it  for  the  purpose, and,  more- 
over, such  an  one,  as  may  be  applied  as  well  for  potash  as  for 
soda-lyes.  e  have,  heretofore,  for  a  testing  acid,  recom- 
mended nitric  acid  ;  but  its  treatment  offers  to  those  who  are 
not  chemists  certain  difficulties,  and  for  this  reason  we  would 
recommend  to  soap  manufacturers  crystallized  oxalic  acid.  It 
has  in  its  crystallized  state  always  the  same  composition,  and 
can, as  it  is  dry,  always  be  accurately  weighed.  63  grammes 
(2.2  ozs.)  of  purified  oxalic  acid  (in  case  of  necessity  the 
comnaercial  oxalic  acid  may  be  used)  are  dissolved  into  1  litre 
of  water.  It  corresponds  to  47.11  grammes  (1.65  ozs.)  caustic 
potash,  and  31  grammes  (1.09  ozs.)  caustic  soda,  each  cubic 


256  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


centimetre,  therefore,  0.047  grammes  (0.725  grains)  potash 
and  0.031  grammes  (0.478  grains)  soda. 

If  a  lye  is  to  be  estimated,  take  into  a  beaker  glass,  or  still 
better,  in  a  porcelain  cup  10  cubic  centimetres  (2.70  flui- 
drachms)  thereof,  then  add  about  10  drops  of  litmus  tinc- 
ture, and  then  by  means  of  a  -^q  cubic  centimetre  (0.027  flui- 
drachm)  graduated  pipette,  add  the  oxalic  acid  solution  until 
the  blue  color  of  the  liquid  has  changed  into  an  onion-red. 
Supposing  now  we  had  by  this  transaction  used  upon  a  pot- 
ash lye  10  cubic  centimetres  (2.70  fluidrachms)  oxalic  acid, 
then  there  are  in  the  10  cubic  centimetres  of  the  applied  lye 
0.47  grammes  (7.25  grains)  potash,  or,  if  soda  lye  had  been 
estimated,  0.31  grammes  (4.78  grains)  soda  contained  in  the 
lye;  the  one  lye  contains,  therefore, 4.71  grammes  (72.7 grains) 
or  per  cent,  potash,  the  other  3.10  grammes  (47.83  grains) 
per  cent.  soda.  To  show  at  once  that  in  such  like  tests  it  is 
not  important  to  obtain  the  highest  degree  of  accuracy,  that 
is  to  have  absolutely  pure  oxalic  acid,  we  will  suppose  the 
applied  oxalic  acid  had  contained  but  95  per  cent,  pure  oxalic 
acid,  an  amount  of  impurity  hardly  ever  found.  In  fact  there 
would  in  such  a  case  as  is  shown  above  if  10  cubic  centime- 
tres (2.70  fluidrachms)  oxalic  acid  had  been  used,  not  4.711 
grammes  (72.69  grains)  potash,  or  3.10  grammes  (47.83  grains) 
soda,  have  been  the  proper  conteiits  of  the  lyes,  but  only  4.711 : 
0.95  =  4.4  (67.9  grains)  potash,  respectively  2.945  per  cent,  soda, 
so  that  the  difl:erence  in  both  cases  amounts  to  about  ^  per  cent. 
But  another  test  of  the  lye  can  be  made  in  this  manner,  by 
placing  with  a  pipette  4.71  cubic  centimetres  (1.27  flui- 
drachms) potash-lye,  or  of  a  soda  lye  3.1  cubic  centimetres 
(0.84  fluidrachm)  in  a  cup,  bluing  it  with  litmus  tincture, 
and  then  by  means  of  normal  oxalic  acid  solution  titrate 
until  an  onion-red  color  appears.  In  this  case  the  cubic 
centimetre  of  acid  used,  multiplied  by  10,  gives  the  content 
of  the  caustic  alkalies  without  further  calculation. 

But  it  is  always  best  for  such  tests  to  apply  purified  oxalic 
acid,  for  which  purpose  the  crude  oxalic  acid  is  dissolved  in 
double  its  weight  of  heated  distilled  water  and  the  solution 
filtered,  when  after  cooling  off,  the  acid  will  crystallize  in  a 


THE  FABRICATION  OF  SOAPS. 


257 


sufficiently  pure  condition.  It  is  then  brought  upon  a  filter, 
and  dried  in  the  open  air  upon  tissue  paper  without  warming 
it,  until  a  crystalline  powder  is  formed. 

Whenever  the  application  of  oxalic  acid  seems  too  trouble- 
some, the  test  acid  may  be  sulphuric  acid,  of  which  55  grammes 
(1.93  ozs.)  are  weighed  off  and  diluted  with  water  to  1000 
cubic  centimetres,  one  litre  (2.1  pints).  To  have  this  acid 
mixture  correct,  dissolve  5.3  grammes  (81.78  grains)  fresh 
heated  pure  carbonate  of  soda  in  100  cubic  centimetres  (3.38 
fluid  ozs.)  liquid  ;  of  this  transfer  10  cubic  centimetres  (2.70 
fluidrachms)  by  the  pipette  into  a  porcelain  cup,  adding 
tincture  of  litmus,  and  also  from  a  graduated  pipette  so 
much  sulphuric  acid  until  the  liquid  has  assumed  an  onion- 
red  color,  and  by  warming  again  does  not  again  turn  blue. 
If  the  sulphuric  acid  had  been  correctly  mixed,  then  10  cubic 
centimetres  of  it  would  have  been  accurately  used  ;  to  occa- 
sion that  change  of  color,  generally,  however,  there  will  be — 
according  to  the  above  proportions  between  water  and  sul- 
phuric acid — less  than  10  cubic  centimetres  used  of  the  test- 
ing acid,  and  the  deficiency  must  be  made  up  of  pure  water. 
Supposing,  instead  of  10  cubic  centimetres  (2.70  fluidrachms) 
but  9  cubic  centimetres  (2.43  fluidrachms)  had  been  applied, 
then  to  the  litre  of  testing  acid,  99  cubic  centimetres  (3.34 
fluid  ozs.)  water  must  be  added. 

We  have  already  explained,  that  in  order  to  determine  the 
strength  of  a  lye  with  some  degree  of  accuracy,  we  carmot 
depend  upon  a  hydrometer,  but  will  prove  by  an  example 
what  difierences  may  ensue  under  certain  conditions.  Thus 
a  lye  containing  14.52  per  cent,  of  caustic  soda  of  the  specific 
gravity  of  1.255  =  29.5°  B.,  and  according  to  this  should  have 
contained  16.635  per  cent,  of  soda.  If  the  requisite  quantity 
of  the  lye  for  decomposing  the  neutral  fat  had  been  deter- 
mined by  means  of  a  hydrometer  in  this  case,  we  should  have 
applied  2  per  cent,  of  soda  less  than  was  necessary  for  a  com- 
plete saponification.  The  soda  from  which  that  lye  had  been 
prepared  contained  72  per  cent,  anhydrous  carbonate  of  soda, 
hence  we  have  an  inferior  article.  Under  certain  conditions 
a  hydrometer  may,  of  course,  be  used  for  determining  the 
17 


258 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


value  of  alkali  contained  in  certain  (equal)  sorts  of  potash  or 
soda;  that  is  when  large  quantities  thereof  are  on  hand  and 
have  to  be  worked  up.  In  such  case  the  contents  of  the  alkali 
are  discovered  in  the  alkalimetric  way  and  compared  w^th  the 
specific  gravity  or  the  degrees  Baume  or  those  of  another 
scale.  Then  as  long  as  that  supply  holds  out  the  alkalimetric 
tests  may  be  dispensed  with  and  the  hydrometer  may  be  used. 

In  order  to  obtain  a  certain  basis  for  this,  there  have  been 
found  by  experiment — for  soda  lye — the  results  indicated  in 
the  two  following  tables,  from  which  it  may  be  seen  about 
how  much  of  the  caustic  soda  has  to  be  deducted  from  the 
degree  of  Baume's  hydrometer. 

One  of  the  tables  contains  experiments  with  86  per  cent, 
soda,  the  other  with  72  per  cent.  soda. 


I.  86°  Soda. 

Specific  gravity. 

Degrees  Bauifle. 

Should  contain. 

Contains. 

1.2333  = 

32.15 

14.554 

13.890 

1.1166  = 

24.20 

7.635 

6.945 

1.0583  = 

9.60 

4.231 

8.472 

II.  72°  Soda. 

1.2548  = 

84.5 

16.636 

14.360 

1.1274  =;= 

19.5 

8.646 

7.180 

1.0637  = 

10.2 

4.574 

8.590 

If  the  estimations  of  the  hydrometer  have  been  compared 
with  the  results  of  the  alkalimetric  test,  we  can  as  long  as  the 
same  sort  of  soda  is  worked,  for  approximate  determination  of 
the  lyes  of  caustic  soda,  apply  the  hydrometer  also.  This  is 
done  by  deducting  according  to  the  degrees  of  soda  a  certain 
portion  from  the  per  cents,  show^n  by  the  scale  of  the  hydro- 
meter. We  do  not  wish  to  recommend  this  method,  but  there 
are  many  soap  factories  where  the  hydrometer  cannot  be  dis- 
pensed with,  and  for  such  the  statements  above  may  have 
some  value. 


THE  FABRICATION  OF  SOAPS. 


259 


Table  of  the  contents  of  Anhydrous  Potash  with  the  corresponding 
specific  gravities  and  degrees  of  the  hydrometer  according  to 
Baume  {calculated  by  Tunnerniann)  at  15°  (7.  (59°  F.). 


Specific 
gravity. 

Degrees 
according  to 

Baume 
approximate 

Per  cent,  of 
potash. 

20  1.  (6.29  gal.) 
contain  kilogr. 
NaO, 

Quantity  of  fat  which  in 
100  1.  ('.^6.5  gallons)  of  the 
corresponding  lyes  will 
saponify. 

1.3300 

36° 

28.290 

7.52 

228  kg. 
215  " 

1.3131 

34 

27.158 

7.09 

1.2966 

33 

26.027 

6.75 

205  '* 

1.2803 

32 

24.895 

6.37 

193  " 

1.2648 

30 

23.764 

6.02 

182 

1.2493 

28 

22.632 

5.66 

171  " 

1.2342 

27 

21.500 

5.30 

161 

1.2268 

26 

20.935 

5.14 

156 

1.2122 

25 

19.803 

4.80 

145 

1.1979 

23 

18.671 

4.50 

136  " 

1.1839 

22 

17.540 

4.15 

126  " 

1.1702 

21 

16.408 

3.84 

116  '* 

1.1568 

19 

15.277 

3.53 

107  " 

1.1437 

18 

14,145 

3.22 

99 

1.1308 

17 

13.013 

2.94 

89 

1.1182 

15 

11.822 

2.64 

80 

1.1059 

14 

10.750 

2.38 

72 

1.0938 

12 

9.619 

2.10 

64 

1.0819 

11 

8. 437 

1.85 

56 

1.0703 

10 

7.355 

1.57 

48 

1.0589 

7 

6.214 

1.32 

40  " 

1.0478 

6 

5.022 

1,05 

32  " 

1.0369 

5 

3.961 

0.82 

25  " 

1.0260 

3 

2.829 

0.58 

18 

1.0153 

2 

1.697 

0.34 

10  " 

1.0050 

1 

0.5658 

0.11 

3.6" 

The  second  and  fourth  columns  are  added  by  Perutz,  and 
the  latter  is  especially  calculated  for  the  convenience  of  soap 
boiling  establishments,  and  is  valuable  for  reference. 

Dalton  has  lii<:ewise  furnished  a  table  respecting  the  potash 
contents  of  lyes,  according  to  their  specific  gravities,  which, 
however,  differs  2  per  cent,  from  the  above.  But  as  it  ex- 
tends also  to  lyes  of  greater  specific  gravities  we  deem  it 
desirable  to  add  it  here. 


260  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Specific  gravity. 

Degrees 
according  to 
Baum6. 

Per  cent,  of  potash. 

Quantities  of  fat  which  in  100 
kil.  (220  lbs.)  of  the  lyes 
are  saponified. 

i  bo 

58 

01. Z 

OA'7  1^-^ 

307  Kg. 

l.bv 

K  A 

04 

46. 7 

1  KO 

A  Q 

4y 

/ion 

O  K  O  ii 

zoo 

1    A  7 
1.4/ 

4d 

O  'I  A 

1    A  A 

1.44 

44 

3b. o 

o  o  O       (  ( 

1    A  A 

1.44 

A  O 

4o 

OA  A 

o4.4 

OA/?        (  ( 

zUb 

1  QQ 
l.OtJ 

/I  A 

4U 

Q  O  A 

1  y4 

1  .OO 

Q  O 

oo 

OCk  A 

1  <  b 

O  K 
OO 

ib..i 

1  f;  7      <  t 
10  / 

1.28 

31 

23.4 

140  " 

1.23 

27 

19.5 

117  " 

1.19 

23 

16.2 

97  " 

1.15 

19 

13.0 

78  " 

1.11 

14 

9.5 

58  " 

1.06 

8 

4.7 

26  " 

In  the  above  table  it  is  supposed  that  141  parts  potash,  on 
an  average,  saponify  860  equivalents  of  fat;  but  we  can 
operate  more  accurately  when  the  equivalents  for  the  dif- 
ferent fats  are  the  basis  for  this  calculation.  The  figures  in 
the  fourth  column  are  then  changed  in  the  same  ratio  as  the 
equivalent  becomes  greater  or  smaller  than  that  accepted  by 
Perutz,  viz.,  860. 


THE  FABRICATION  OF  SOAPS. 


261 


Table  of  the  contents  of  Anhydrous  Soda  with  the  corresponding 
specific  gravity  and  hydronieteric  degree  of  Baume^  according  to 
Tunnermann^  to  which  Perutz  has  likewise  added  the  quantities 
of  the  fats^  v^hich  are  saponified  by  lyes  of  various  strengths. 


vity. 

a 

soda. 

^  . 

sa- 
fat. 

>3J 

s 

soda. 

1 

00    ,  -w 

ej 

bo 
u 

03 

o 

CO 

■^rd 

a 

ci 

pa 

o 

« 

-.^^ 

to  "  7* 

*9 

<u 

<o 

(O 

u 

bo 

(3 
o 
w 
u 

^*  dis 

tS 

a> 

s 

o 

^i! 
,^  a 

100  1.  (5 
of  the 
ponitj 

CO 

<D 

o  © 

o  «  M 

0=w  o 
o  O  P< 

<s> 
Ph 

o  o 
o  «  « 

1.4285 

43 

30.220 

8.63 

416.7 

1.2392 

27 

15.110 

3.74 

181.2 

1.4193 

43.5 

29.616 

8.41 

406.5 

1.2280 

26 

14.506 

3.56 

172.3 

1.4101 

42.0 

29.017 

8.18 

395.7 

1.2178 

25 

13.901 

3.38 

163.7 

1.4011 

41.0 

28.407 

7.96 

385.0 

1.2058 

24.5 

13.297 

3.21 

155.0 

1.3923 

40.5 

27.802 

7.74 

374.3 

1.1948 

23 

12.692 

3.03 

146.6 

1.3836 

39.7 

27.200 

7.53 

364.0 

1.1841 

22 

12.088 

2.88 

139.4 

1.3751 

39 

26.594 

7.31 

353.7 

1.1734 

21 

11.484 

2.70 

130.3 

1.3668 

38.5 

25.989 

7.10 

343.6 

1-1630 

20  , 

10.879 

2.53 

122.3 

1.3586 

38.0 

25.385 

6.89 

333.5 

1-1528 

19 

10.275 

2.37 

114.6 

1.3505 

37.3 

24.780 

6.69 

323.7 

1.1428 

18 

9.670 

2.21 

106.8 

1.3426 

36.7 

24.176 

6.50 

314.0 

1.1330 

17 

9.066 

2.05 

99.4 

1-3349 

36 

23.572 

6.30 

304.3 

1.1233 

16 

8.462 

1.91 

91.9 

1.3273 

35 

22.967 

6.08 

294.1 

1.1137 

15 

7.857 

1.75 

84.6 

1.3198 

34.5 

22.363 

5.90 

285.4 

1.1012 

13.5 

7.253 

1.59 

77.4 

1.3143 

34.2 

21.894 

5. 75 

278.3 

1.0948 

12 

6.648 

1.46 

70.4 

1.3125 

34 

21.758 

5.70 

276.2 

1.0855 

11 

6.044 

1.31 

63.4 

1.3013 

33.5 

21.154 

5.52 

267.1 

1.0764 

10 

5.440 

1.17 

56.6 

1.2982 

33 

20.550 

5.53 

258.0 

1.0675 

9 

4.835 

1.03 

49.9 

1.2912 

32.4 

19.945 

5.16 

249.0 

1.0587 

7 

4.231 

0.89 

43.3 

1.2843 

31.6 

19.341 

4.97 

240.2 

1.0500 

6 

3.626 

0.76 

36.8 

1.2775 

31 

18.730 

4.79 

231.4 

1.0414 

5.6 

3.022 

0.63 

30.4 

1.2708 

30.5 

18.132 

4.61 

222.9 

1.0330 

4.2 

2.418 

0.50 

24.1 

1.2642 

30 

17.518 

4.43 

214.2 

1.0246 

3 

1.813 

0.37 

17.9 

1.2578 

29 

16.923 

4.26 

205.9 

1.0163 

2 

1.209 

0.25 

11.8 

1.2515 

28.5 

16.319 

4.09 

197.5 

1.0081 

1 

0.604 

0.13 

5.9 

1.2453 

28 

15.714 

3.92 

189.3 

For  finding  the  contents  of  soda  in  the  lye,  Dalton  has 
also  furnished  a  table,  showing  the  various  specific  gravities 
of  soda  contained  in  the  lyes.  The  results  vary  materially 
from  those  stated  by  Tiinnermann,  which  perhaps  have  their 
reason,  because  the  latter  may  not  have  used  a  perfectly  pure 
— carbonic  acid  free — lye,  for  his  analysis. 


262  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Specific 
gravity. 

Degrees 
Baume. 

Contents 
of  soda. 

100  kg.  (220 
lbs.)  or  the 
lye  (ia  the 
margin)  sa- 
ponify fats. 

Specific 
gravity. 

Degrees 
Baume. 

Contents 
of  soda. 

100  kg.  (220 
lbs.)  of  the 
lye  (in  the 
margin)  sa-  . 
ponify  fats. 

2.95 

70 

77.8 

720  kg. 

1.40 

41 

29.0 

270  kg. 

1.85 

66 

63.6 

596 

1.36 

38 

26.0 

242  " 

1.72 

60 

5-4.8 

498  " 

1.32 

35 

23.0 

224  ' 

1.63 

56 

46.6 

431  " 

1.29 

32 

19.0 

168 

i.se 

52 

41.2 

381  " 

1.23 

27 

16.0. 

149  " 

1.50 

48 

36.8 

346 

1.18 

22 

13.0 

121 

1  47 

46 

34.0 

314 

1.12 

16 

9.0 

83  " 

1.44 

44 

31.0 

287  " 

1.06 

8 

4.7 

44  " 

The  fats  and  oils  and  the  fatty  acids  as  they  are  received 
by  soap  manufacturers,  are  usually  in  a  condition  for  imme- 
diate use,  but  occasionally  there  may  be  impurities  of  such 
a  character  that  they  will  require  to  be  removed  hefore  they 
are  made  into  so^p.  If  they  are  merely  foreign  substances 
a  melting  and  straining  may  prove  sufficient,  or  there  may  be 
adulterations.  This  falsification  we  have  pointed  out  and 
given  some  tests  for  in  another  section ;  should  the  tallows, 
greases,  or  oils  prove  very  impure  they  can  be  improved  very 
much  by  melting  to  about  40°  C.  (104°  F.),  and  adding  about 
two  per  cent,  of  strong  alkali,  say  38^  B.,  stirring  gently  at 
this  temperature  for  ahout  a  quarter  of  an  hour  and  then 
allowing  to  rest  and  cool.  The  impurities  will  fall  to  the 
bottom,  and  the  purified  grease  can  be  removed  therefrom. 

It  is  generally  conceded,  and  in  our  judgment  very  truly, 
that  there  is  no  oil  or  fat,  though  in  itself  containing  several 
constituents,  which  used  alone  makes  a  faultless  soap.  Thus 
tallow  or  curd  soap  becomes  in  drying  too  hard  and  almost 
insoluble,  and  so  with  olive  oil  soap,  which  has  the  same  pro- 
perty, and  on  the  other  hand,  soaps  made  with  the  drying 
oils  (linseed,  poppy,  etc.)  are  too  soft  and  cannot  be  made 
sufficiently  hard  for  use  as  solid  soaps,  and  are  consequently 
mostly  made  into  soft  soaps  with  potash  lye,  which,  by  its 
hygroscopic  property,  always  remain  soft  and  when  exposed 
to  the  air  absorb  water  and  are  constantly  getting  softer. 

So  that  knowing  the  different  properties  of  the  fatty  bodies 
with  their  behavior  when  combined  with  the  alkalies,  it  is 


THE  FABRICATION  OF  SOAPS. 


268 


necessary  so  to  mix  the  diflerent  oils  and  fats,  and  in  such 
proportions  that  considering  the  diflerent  properties  of  each, 
bj  judicious  mixture,  may  be  produced  a  soap  having  proper- 
ties suitable  for  its  intended  uses.  The  mixtures  of  the  dif- 
ferent ingredients  will  be  given  when  we  discuss  the  manu- 
facture of  each  kind  of  soap  and  with  them  several  formulas 
if  necessary. 

In  making  soaps  by  boiling  with  an  open  fire,  with  steam, 
or  surcharged  steam,  or  by  whatever  appliance  or  methods 
the  manufacturer  may  possess,  it  is  necessary  in  the  first  place 
to  determine  the  proper  proportions. 

According  to  the  information  already  given  as  to  the 
equivalents  for  the  fiits,  we  suppose  that  50  kilog.  (110  lbs.) 
pure  fat  (which  must  not  be  mixed  with  cocoa-nut  oil)  de- 
mand about  6  kilog.  (13.2  lbs.)  caustic  soda  or  8.5  kilog.  (18.7 
lbs.)  caustic  potash.  This  is  indeed  somewhat  in  excess  of 
the  real  necessity,  but  a  little  surplus  is  not  injurious,  as 
the  lyes  are  seldom  perfectly  free  from  carbonate,  and  carbo- 
nated alkali  does  not  easily  combine  with  neutral  fats.  On 
this  supposition,  we  will  answer  the  question,  How  many 
kilogrammes  of  fat  might  be  saponified  by  1000  litres  (265 
gallons)  of  a  soda  lye  of  20°  B.  =  1.163  specific  gravity  = 
10.879  per  cent.?  1000  litres  weigh  1163  kilog.  (2559  lbs.); 
with  10.879  per  cent,  soda,  the  same  contain  126.5  kilog. 
(278.3  lbs.)  caustic  soda;  since  according  to  our  supposition 
6  kilog.  (13.2  lbs.)  of  this  50  kilog.  (110  lbs.)  fat  saponify, 

hence  126.5  kilog.  saponify  ^^^'^^^  ^  =  1054.2  kilog.  (2319 

lbs.)  fat. 

If,  on  the  other  hand,  we  have  1000  litres  (265  gallons)  pot- 
ash lye  of  20"^  B.  or  1.163  specific  gravity,  which  according  to 
the  table  (heretofore  given)  contains  15.842  per  cent,  potash, 
and  suppose,  that  50  kilog.  (110  lbs.)  fat  require  8.5  kilog. 
(18.7  lbs.)  for  saponification,  then  those  1000  litres  (weighing 
1163  kilog.)  contain  184.2  kilog.  (405.24  lbs.)  potash  and 

hence       g  ^      =  1083.5  kilog.  (2384  lbs.)  fat  would  be 

saponified. 


264  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Although  in  the  two  preceding  examples  we  have  supposed 
the  quantity  of  the  lye  according  to  weight,  yet  it  is  more 
convenient  for  all  operations  on  a  larger  scale  to  measure  the 
liquids  instead  of  weighing  them.  But  the  proportions  there- 
by become  the  more  varied  the  stronger  the  lyes  are.  Though 
500  cubic  centimetres  (16.9  fluid  ozs.)  water  weigh  also  J  kilog. 
(1.1  lbs.),  yet  500  cubic  centimetres  of  lye  weigh  so  much 
more  than  J  kilog.,  as  this  lye  is  stronger.  It  is  therefore 
easier  and  more  to  the  point  in  question  to  give  the  contents 
of  a  lye  as  to  its  value  of  caustic  alkali,  according  to  its 
measure  than  its  weight.  The  figures  in  the  tables  as  to  the 
contents  of  the  lye  relate,  how^ever,  to  weight  proportions ; 
but  they  can  be  easily  changed  into"  volume  per  cent,  by 
multiplying  the  former  by  the  specific  gravity  of  the  lye. 
In  the  preceding  examples,  there  would  hence  be  in  the  case 
of  soda  of  10.879  weight  per  cent.  12.67  volume  per  cent., 
and  of  15.842  weight  per  cent,  potash,  we  would  have  18.42 
volume  per  cent. ;  hence  in  1000  litres  (265  gallons)  are  con- 
tained 126.5  kilog.  (278.3  lbs.)  soda,  or  184.2  kilog.  (405.24  lbs.) 
potash,  the  same  as  above.  The  measuring  method  at  once 
commends  itself  for  this  reason,  because  we  obtain  directly 
by  the  investigation  of  the  lye  the  volume  per  cent. 

If  in  this  manner  the  supply  of  lye  is  made  the  issue  for 
determining  the  quantity  of  a  boiling,  we  will  never  be  in  a 
quandary  on  account  of  the  want  of  lye  during  the  operation 
of  boiling.  That  we  may  also  proceed  in  a  reversed  way,  as 
soon  as  we  are  sure  of  having  a  suflicient  supply  of  lye,  and 
as  soon  as  we  are  acquainted  with  the  strength  of  the  same, 
and  how  much  of  this  lye  is  required  to  saponify,  for  in- 
stance 500  kilog.  (1100  lbs.)  fat,  will  thus  become  obvious. 
Supposing  it  is  intended  to  make  a  boiling  of  375  kilog.  (825 
lbs.)  fat  by  means  of  soda,  then  we  would  need  of  pure  lye, 
which  contains  6  percent,  caustic  soda  for  each  50  kilog.  (110 
lbs.)  fat  100  kilog.  (220  lbs.),  and  hence  for  those  375  kilog. 
fat  750  kilog.  (1650  lbs.)  of  this  lye  would  be  required. 

We  use  for  these  calculations  the  tables  of  Perutz,  which 
we  have  given  on  pages  259  and  261,  and,  for  the  sake  of 
convenience,  we  have  here  also  added  the  weight  of  potash  or 


THE  FABRICATION  OF  SOAPS. 


265 


soda  contained  in  10  litres  (2.6  gallons)  lye — and  have  recal- 
culated into  measures.  These  tables  containing  all  sorts  of 
lyes,  from  the  strongest  to  the  very  weakest,  it  is  by  their 
aid  very  easy  to  find  the  correct  quantities  of  alkali,  even  if 
we  are  compelled  to  apply  lyes  of  various  strengths. 

A  few  examples  will  make  this  still  more  apparent.  Sup- 
posing we  had  2000  kilog.  (4400  lbs.)  fat  to  boil  into  soft  soap, 
it  would  require,  if  8.16  kilog.  (17.95  lbs.)  potash  saponify  50 

kilo.  (110  lbs.)  fat  "^^''^^^/^^^  =  326.4  kilog.  (718  lbs.).  Of 

lye  we  have  one  of  21°  B.  and  another  of  10°  B. ;  each  of  the 
lyes  is  to  furnish  one-half  of  the  requisite  potash  ;  hence 
163.2  kilog.  (359  lbs.). 

In  the  table  for  potash  we  find  that  in  20  litres  (5.29  gal- 
lons) of  the  lye  of  21  °  B.  3.84  kilog.  (8.45  lbs.)  potash  are  con- 
tained, hence  we  have  the  rate  3.84  :  163.2  ==  20  :  a: ;  x  = 
950,  and  we  have  therefore  to  take  950  litres  (251  gallons)  of 
this  lye.  Of  the  lye  of  10°  B.,  20  litres  (5.29  gallons)  contain 
1.57  kilog.  (3.45  lbs.)  potash,  hence  157  :  163.2  =  20  :  ;  a:  = 
2079  ;  of  this  lye  there  are  consequently  to  be  measured  ofi' 
2079  litres  (550  gallons).  If  |  of  the  strong  lye  is  to  be  taken 
and  f  of  the  weak,  the  calculation  would  be  fixed  as  follows: 

5  X  326.4     16,320                           2  x  326.4  652 
 y  =  — >^ —  =  2334  kilog.,  and   ~ 

93.2  kilog.  (205  lbs.) ;  we  have  hence  to  take  3.84  :  233.14 
20  :     1214  litres  (321  gallons)  of  the  strong,  and  of  the  weak 
1.57  :  93.2  =  20  :  :c  =  1187  litres  (314  gallons). 

In  the  same  manner  the  calculation  is  carried  out  if  the 
point  in  question  is  the  saponification  of,  for  instance,  1000 
kilog.  (2200  lbs.)  tat,  by  means  of  caustic  soda.  To  do  this 
107.4  kilog.  (236.28  lbs.)  caustic  soda  would  be  requisite, 
whereof  one-half  is  applied  for  the  so-called  process  of  boil- 
ing the  paste  (preliminary  operation)  with  a  weaker  lye.  On 
hand  are :  a  lye  of  30°  B.  and  another  of  12°  B.  The  former 
contains  in  20  litres  (5.29  gallons)  4.43  kilog.  (9.75  lbs.)  of 

53  7  X  20 

caustic  soda  (one-half  of  the  entire  quantity)  take  — — 
=  250.4  litres  (66  gallons). 


266  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


The  weaker  lye  of  12°  B.  contains  in  20  litres  (5.29  gallons) 
1.46  kilog.  (3.21  lbs.)  caustic  soda,  and  to  obtain  also  in  this 
case  53.7  kilog.  (118  lbs.)  caustic  soda,  we  will  have  to  apply 
53  7  X  20 

~\jQ       =  736  litres  (194  gallons). 

These  few  examples  will  suffice  to  show  how  to  use  the 
tables,  and  also  how,  by  means  of  the  same,  the  correct  pro- 
portion between  fat  and  alkali  may  be  calculated  in  advance. 


Hard  Soaps  (Soda  Soaps). 

We  begin  with  the  fabrication  of  the  solid  (curd  or  grain) 
soaps  made  with  soda  lye.  They  are  such  soaps  as  in  the 
process  of  boiling  are  cut,  or  freed  from  their  superfluous 
water  by  means  of  culinary  salt,  and  are  the  white,  yellowish, 
or  marbled  soaps. 

To  make  a  good  Marbled  or  Marseilles  Soap  the  operation 
is  divided  into  the  following  different  parts. 

1.  The  pasting  or  empatage. 

2.  The  separation  or  relargage. 

3.  The  clear  boiling  or  eoction. 

4.  The  mottlino;  or  marblino:. 

5.  The  framing. 

In  making  the  paste,  only  one-half  of  the  quantity  of  caus- 
tic soda  is  applied,  which  is  necessary  for  a  perfect  saponifi- 
cation of  the  fat  which  is  taken  to  be  worked  up;  but  this 
quantity  is  also  divided  into  two  lyes  of  different  strengths, 
and  for  the  first  application  the  weaker  \yQ  is  used,  so  that 
the  boiling  commences  with  the  fourth  part  of  the  entire 
quantity  of  caustic  soda. 

A  certain  quantity  of  lye  is  now  placed  in  the  kettle  to  be 
boiled,  and  then  the  fat  is  added,  and  for  marbled  or  Mar- 
seilles soap  olive  oil  with  about  10  to  20  per  cent,  of  a  drying 
oil  is  put  in.  After  a  short  time  the  mass  is  again  brought 
to  a  boil,  whereby  it  bubbles  up  under  ebullition.  For  check- 
ing the  boiling  over  the  fire  is  diminished,  and  while  the 
mass  is  being  gently  stirred  it  is  permitted  to  continue  to 
boil  until  all  frothing  has  ceased,  and  the  so-called  paste  is 


THE  FABRICATION  OF  SOAPS. 


267 


formed.  The  mass  has,  in  this  condition  of  the  operation,  a 
yellowish  white  appearance,  and  if  a  sample  of  it  is  taken 
out  with  a  spatula,  it  can  be  drawn  into  long  threads  of  a 
white  color.  The  soap  after  continuous  boiling  having  as- 
sumed a  greater  consistency,  receives  a  gradual  addition — at 
intervals  of  about  half  an  hour — of  the  second  portion  of  lye, 
and  the  boiling  is  kept  up  during  several  hours,  the  better 
to  perfect  the  combination  of  the  soda  with  the  fat.  In 
order  to  facilitate  this  combination,  a  little  carbonate  of  soda 
is  occasionally  added;  much  better  suited  for  this  purpose, 
however,  is  a  small  portion  of  finished  soap,  which  causes 
the  formation  of  an  emulsion-like  mixture,  a  condition  which 
greatly  hastens  the  saponification.  When  a  perfect  union  of 
the  fat  and  the  alkali  has  taken  place  the  second  operation, 
called  the  cutting  of  the  pan  or  the  separation  of  the  surplus  water 
from  the  soap,  thereby  to  make  the  same  more  consistent,  is 
attended  to,  when  after  the  preliminary  boiling  a  perfect 
union  of  the  fat  with  the  lye  has  taken  place.  For  this  ope- 
ration we  take  either  a  strong  salted  soda  lye  or  culinary 
salt.  The  latter,  for  reasons  stated  when  this  subject  was  under 
discussion,  must  be  refined.  It  is  applied  dry  or  in  solution, 
and  of  the  one  or  the  other  we  add  as  long  as  the  soap  and  the 
lye  become  separated,  which  is  ascertained  by  noticing  when 
the  soap  begins  to  boil  into  broad  and  smooth  plates,  and  upon 
the  spatula  separating  from  the  lye  in  pieces,  and  a  sample 
of  it,  being  cooled  off  on  a  glass  plate,  is  no  longer  soft  and 
smeary,  but  can  be  removed  tolerably  dry.  Another  sign  of 
the  complete  separation  is  that  the  hot,  clear  lye  after  cool- 
ing off  does  not  congeal  to  a  jelly-like  mass.  There  is  gene- 
rally no  danger  that  the  soap  will  not  completely  separate, 
because  a  little  surplus  of  culinary  salt  does  not  injure  it. 
How  much  of  salt  is  necessary,  in  proportion  to  the  mate- 
rials which  are  being  worked  up  (fat  and  alkali)  to  cause 
separation,  cannot  be  reckoned  in  advance,  since  this  is  de- 
pendent on  the  concentration  of  the  lye  applied  and  the 
greater  or  less  time  required  for  boiling,  whereby  it  concen- 
trates. The  surest  mode  is  repeated  proving,  whereby  we 
convince  ourselves  of  the  state  of  the  mass. 


268  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES 


The  action  of  the  culinary  salt  does  not  always  succeed  at 
once,  even  if  it  is  applied  in  soluble  form,  although  it  may  thus 
cause  a  somewhat  quicker  operation.  The  more  diluted  the 
lye  is,  the  more  culinary  salt  will  be  needed  for  separation. 
Then,  when,  in  consequence  of  an  increased  boiling,  a  greater 
concentration  of  the  lye  has  been  produced  a  separation  will 
ensue ;  for  as  has  already  been  stated,  the  separation  of  the  soap 
does  not  so  much  rest  upon  the  absolute  quantity  of  culinary 
salt  to  a  given  quantity  of  soap,  as  upon  the  insolubility  of  the 
latter  in  a  lye  containing  culinary  salt,  of  a  certain  concentra- 
tion. The  manner  in  which  the  soap  boils,  is  likewise  a  crite- 
rion as  to  whether  the  separation  is  complete.  If  instead  of  a 
smooth,  lustrous  surface,  which  is  furrowed  into  small  sections 
and  circles,  larger  and  rough  divisions  are  visible,  which  are 
broken  by  steam  under  formation  of  bubbles,  whereby  the 
soap  begins  to  rise,  it  may  be  presumed  that  the  separation  of 
the  soap  is  completed.  Moreover,  the  sub-lye  must  on  no 
account  have  a  touch  or  caustic  taste,  nor  will  this  occur 
if  the  operation  has  been  correctly  performed,  because  the 
oil  on  hand  is  in  double  the  quantity  that  the  alkali  present 
can  absorb  for  forming  a  neutral  soap.  But  if  there  should 
despite  all  this  be  some  unsaponified  oil  therein,  then  a 
mistake  has  been  made,  the  cutting  of  the  pan  has  been  pre- 
mature, and  must  now,  after  the  soap  has  been  again  rendered 
into  paste  by  adding  water,  again  boil  until  all  the  alkali 
becomes  bound,  and  the  sub-lj^e  assumes  a  sweetish-salt  taste. 
A  further  addition  of  culinary  salt  is  not  needed,  and  the 
soap  reseparates  without  this,  when  the  sub-lye,  by  the  evapo- 
ration of  water  is  again  so  concentrated,  that  it  will  no 
longer  dissolve  any  soap.  After  a  complete  separation  havi  ng 
ensued,  the  soap  must  remain  a  few  hours  longer  in  the 
kettle,  during  which  time,  the  lye  settles  on  the  bottom,  and 
is  then  drawn  out  by  means  of  the  waste  pipe,  which  is  in 
the  bottom  of  the  kettle.  Where  such  a  pipe  is  not  present, 
the  removal  of  the  sub-lye  is  by  a  portable  pump,  which  has 
its  barrel  on  the  lower  end,  or  the  soap  is  ladled  from  off  the 
sub-lye  into  the  cooling  vat,  which  stands  close  to  the  boil- 


THE  FABRICATION  OF  SOAPS. 


269 


ing  kettle.  The  soap  is  now  prepared  for  the  third  opera- 
tion of  the  coction  or 

Clear-boiling. — For  this  operation,  after  removal  of  the 
sub-lye,  the  necessary  lye  is  added  to  the  soap,  or  if  this  is 
still  in  the  cooling  vat,  then  it  is  placed  in  the  kettle,  adding 
the  soap  from  the  cooling  vat  to  it,  and  heating  the  entire 
mass  till  it  boils.  Some  manufacturers  divide  even  the  lye 
necessary  for  a  perfect  saponification,  and  boil  the  soap 
first  with  one-half  of  the  same,  and  allow  all  the  sub-lye 
thus  produced — having  imparted  all  its  alkali — to  flow  out, 
whereupon  the  same  operation  is  repeated  with  the  other 
half.  This  may  be  suitable  in  those  cases  where  a  very  im- 
pure fat  is  worked  up,  but  whenever  the  fats  are  pure,  such 
a  custom  is  at  least  superfluous.  It  would  be  best,  from  the 
start,  to  pay  more  attention  to  a  careful  cleaning  of  the 
fat  by  remelting  and  depositing,  a  process  which  under  all 
circumstances  is  much  easier  than  a  boiling  upon  the  so-called 
second,  third,  and  fourth  waters.  Pure  fats  may  even  be 
boiled  and  finished  upon  one  water,  so  that  the  letting  oflc' 
of  the  sub-lye,  or  a  repeated  scooping  of  the  soap  into  a  cool- 
ing vat,  becomes  entirely  superfluous.  Only  if  dark  colored 
fats  are  used,  which  in  a  great  measure  impart  their  color 
to  the  sub-lye,  and  partly  also  to  the  water  which  is  con- 
tained in  the  soap,  it  may  be  necessary  to  boil  in  two  or 
three  waters.  This  of  course  is  dependent  on  the  color,  which 
each  withdrawn  lye  should  show. 

During  the  clear-boiling,  the  soap  should  boil  as  tenaci- 
ously as  possible,  that  is,  it  should  slip  ofl:*  with  difficulty, 
when  a  sample  is  taken  out  with  a  spatula.  It  must  become 
almost  pasty,  and  whenever  this  does  not  take  place  at  once, 
after  adding  a  new  quantity  of  lye,  then  the  mass  must  have 
so  much  water  added  thereto,  till  it  again  returns  into  a  glue- 
like substance.  In  this  state,  the  lye  acts  upon  the  not  yet 
completely  saponified  mass,  and  the  process  of  saponification 
takes  place  much  faster.  It  may  hardly  be  necessary  to  re- 
mark, that,  even  if  by  a  too  abundant  addition  of  water,  the 
soap  has  turned  into  a  real  paste,  this  fault  may  be  easily 
remedied  by  the  addition  of  a  little  more  salt.    The  boiling 


270  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


is  continued,  until  all  the  caustic  soda  is  bound,  and  a  perfectly 
neutral  soap  is  produced.  This  is  ascertained,  by  separating  a 
small  sample  of  the  soap-mass  with  a  solution  of  culinary 
salt,  that  is  by  refining  the  soap,  and  then  dissolving  it  in 
a  little  distilled  water.  Thereby  a  clear,  opalescent,  on  no 
account  milky  solution  must  result;  otherwise  there  is  surely 
yet  some  unsaponified  fat. 

After  a  complete  saponification  of  the  fats,  the  soap  will 
become  thicker  and  opaque,  boiling  with  little  bubbles,  by 
continuous,  not  too  violent  boiling.  The  more  water  evapo- 
rates, the  more  lye  collects  upon  the  bottom,  and  the  soap 
becomes  hard,  and  shows  even  at  this  high  temperature  an 
inclination  to  become  solid  ;  deep  furrows  are  formed  on  the 
otherwise  nearly  smooth  surface.  Large  and  shiny  bub- 
bles appear,  and  the  soap  now  boils  into  slabs.  By  taking 
a  sample  and  placing  it  in  the  palm  of  the  hand,  and  rub- 
bing it  until  it  becomes  cold,  it  will  harden  into  dry  and 
glistening  scales,  which  must  show  no  adhesion,  and  may 
even  be  ground  into  powder.  Should  these  characteristics 
be  wanting,  should  it  yet  have  a  smeary  touch,  then  the  soap 
is  either  deficient  in  alkali,  or  the  alkali  used  is  not  suffi- 
ciently caustic,  or  it  has  not  yet  been  boiled  long  enough. 
The  first  case  could  hardly  occur  if  the  proper  proportion  of 
oil  and  alkali  had  been  applied  from  the  start,  but  if  such  is 
the  case,  we  should  not  endeavor  at  once  to  mend  this,  by  a 
fresh  addition  of  alkali,  but  by  continuing  the  boiling  for  a 
longer  period  of  time.  Thus  even  the  carbonate  of  soda  is 
bound — if  its  quantity  is  not  excessively  large — with  the 
fat,  and  thus  a  neutral  soap  is  obtained.  If  longer  boiling 
proves  insufficient,  then  carefully  add  some  caustic  \ye  until 
the  object  is  reached.  Frequent  investigation  of  the  soap,  as 
to  its  solubility  in  distilled  water,  should  not  be  omitted. 
Many  manufacturers,  especially  when  they  think  that  the 
unpropitious  result  is  caused  by  an  insufficient  causticity  of 
the  lye,  add  some  lime-water.  This,  however,  is  for  reasons 
heretofore  stated  most  emphatically  to  be  reproved.  Although 
a  complete  saponification  may  thereby  be  reached,  the  lime- 
soap  formed  in  this  manner  impairs  the  quality  of  the  soap 


THE  FABRICATION  OF  SOAPS. 


271 


far  more  than  the  small  portion  of  unboiled  fat  would.  In 
how  far,  by  a  continued  boiling,  a  good  result  may  be  at- 
tained, can  be  observed  by  the  appearance  of  the  sub-lye. 
For  this  purpose  a  portion  of  the  soap  is  taken  out  of  the 
kettle,  placed  in  a  saucer,  the  lye  completely  separated  and 
cooled  off,  and  the  lye  tested  as  to  its  contents  of  alkali.  If 
by  this  test,  no  free  or  carbonated  alkali,  or  at  least  'but 
very  little  of  it,  is  found,  we  may  presume  that  the  soap  is 
yet  wanting  in  it,  if  it  does  not  show  as  yet  the  normal 
condition.  A  slight  touch,  which  the  sub-lye  may  have,  does 
not  injure  the  soap,  since  it  is  almost  impossible  to  finish  the 
boiling  of  soap,  without  any  touch  at  all.  This  is  quite 
natural  too,  since  entirely  caustic  lye  rarely  or  never  is  ap- 
plied. At  the  first,  the  free  alkali  is  bound  ;  much  more 
difficult  and  slower  is  the  combination  of  the  fat  with  the 
carbonated  alkali,  so  that  to  hasten  the  process  more  caustic 
lye  is  added.  In  this  manner  nearly  all  tlie  carbonated  alkali 
remains  uncombined  and  passes  into  the  sub-lye.  When 
taken  out  it  appears  upon  the  tongue  as  being  too  caustic, 
and  this  touch  must  not  be  deadened  by  the  addition  of  fat. 

The  soap  boiling  correctly  into  slabs,  is  now  kept  boiling 
until  it  becomes  grainy.  Ti]is  last  o[teration  is  the  real  grain 
or  cleaj^-boiling.  The  soap  now  loses  all  superfluous  water, 
and  unites  into  a  small  grain- like  homogeneous-curdle — while 
all  froth  vanishes,  and  when  filled  into  the  frames,  produces 
the  common  grain — (curd)  soap.  But  if  the  curdle  by  ad- 
ding water  or  weak  lye,  is  again  changed  into  a  mass  of  a 
gelatinous  consistency,  which,  however,  remains  separated 
from  the  sub-lye,  then  the  so-called  ground  (or  filled)  soaps 
are  produced. 

The  Grinding  or  Filling  of  the  Soap^  whereby  the  soap  is 
again  changed  into  the  semi-liquid  or  gelatinous  state,  has 
for  its  object  the  purili cation  of  the  soap  from  its  yet  mecha- 
nically combined  dross.  This  is  done  by  imparting  greater 
liquidity  to  it,  and  by  allowing  it  before  casting  it  into  the 
frames  to  remain  for  several  hours  in  the  no  lon2:er  heated 
kettle.  This  grinding  is  performed  by  two  different  modes, 
but  is  always  carried  out  with  water  or  a  very  weak  lye. 


272 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Either  the  lye  still  in  the  kettle  from  the  clear  boiling  remains 
in  it,  and  so  much  water  is  added  until  the  soap  grains  be- 
come liquid — for  this  water  may  be  used,  as  has  been  noted 
above — there  will  still  retain  in  most  cases  a  touch  (this  is 
termed  "the  grinding  from  above) ;"  or  the  salt  lye  is  drawn 
off  and  the  necessary  lye  or  water  with  a  little  salt  is  added 
to  perform  the  grinding,  which  is  termed  "  the  grinding  from 
below."  The  adding  of  salt  is  to  avoid  the  formation  of  paste. 
The  grinding  from  below  is  only  necessary  when  very  impure 
materials  have  been  worked  up. 

The  operation  of  grinding  is  undertaken  over  a  very  hot 
fire  so  that  the  lye  is  constantly  thrown  up,  and  the  boiling 
is  continued  until  broad  slabs  appear,  the  surface  shines  in  a 
honey  yellow  color  or  turns  up  in  rosettes,  and  a  sample  taken 
out  of  it  will  prove  the  correct  quality  of  the  soap.  The 
fire  is  now  extinguished,  and  while  the  kettle  is  covered  with 
the  lid  the  soap  is  allowed  to  settle  for  a  few  hours  and  is 
then  poured  into  the  frames. 

The  Marbling  of  the  Soap. — To  impart  to  the  soap  the  pecu- 
liar clouding  or  marbling,  we  add  to  it  during  the  prelimi- 
nary process  of  boiling,  sulphide  of  sodium  and  sulphate  of 
iron.  Thus  sulphate  of  iron  and  iron-soaps  are  formed,  which 
admix  with  the  soap  and  impart  to  it,  when  quickly  cooled 
off,  a  greenish-black  color.  If  allowed  to  cool  off  slowly  the 
colored  and  insoluble  soaps  contract  into  smaller  points  and 
give  to  the  soap  a  granite-like  mottled  appearance.  If  the 
cooling  ofiT  is  still  more  prolonged  and  the  manipulation 
while  stirring  (an  operation  by  which  the  soap  before  cooling 
ott'  is  stirred  with  an  iron  rod)  is  conducted  with  a  certain 
regularity,  we  obtain  a  beautiful  marbled  soap.  This  isespe- 
ecially  to  be  done  with  tallow  soap,  the  crystallized  grain  of 
which  has  a  great  inclination  to  separate,  and  which  consists 
essentially  of  stearic  soda  soap  that  at  first  congeals  into  a 
solid  mass. 

If  it  is  intended  to  increase  the  marbling,  we  add,  towards 
the  end  of  the  boiling,  Frankfort-black  or  bole  Armenian — of 
the  former  for  500  kilog.  (1100  lbs.)  grain  soap  16f  to  SSJ 
grammes  (0.57  to  1.14  oz.),  and  we  obtain  in  this  way  a  black- 


THE  FABRICATION  OF  SOAPS. 


273 


grayish  marble ;  and  of  the  latter  to  the  same  quantity  of 
soap  100  to  133|-  grammes  (3.52  to  4.69  ozs.),  and  a  brownish- 
red  marbling  appears. 

To  attain  a  handsome  marbling  the  operation  must  be 
performed  with  the  purest  possible  sub-lye  which  contains  at 
the  utmost  but  J  per  cent,  of  the  alkali  and  is  of  about  14°  B. 
strength,  and  we  must  not  add  enough  weak  lye  or  water 
to  liquefy  the  grain — that  is,  no  more  than  is  requisite  to 
diffuse  the  dyeing  matter  equally  through  the  soap.  Finally 
it  must  be  observed  that  the  temperature  during  the  running 
out,  does  not  vary  much  below  or  above  100°  C.  (212°  F.). 

The  marbling  will  be  imperfect  or  does  not  take  place  at 
all,  when  the  soap  mass  is  too  thin,  or  the  temperature  is 
too  high.  Therefore  the  adding  of  lye  must  be  attended  to 
with  care,  commencing  with  the  stronger  and  leaving  off 
with  the  weaker.  The  operation  is  ended,  when  the  soap 
shows  flakes  of  a  greenish  color,  which  float  upon  the  lye, 
and  when  the  grain  becomes  semi-liquid  without  losing  its 
rounded  form.  The  marbling  may,  however,  become  faulty  by 
running  the  soap  into  the  frames  when  too  much  cooled  off,  as 
it  solidifies  too  fast  without  tyivino;  the  various  combinations 
(stearic  and  oleic  soda  soap)  time  to  separate  by  crystallization 
of  the  former.  Because  as  the  stearic  and  palmitic  acids  solid- 
ify at  69°  C.  (156.2°  F.)  and  62°  C,  (143^^.6  F)  respectively, 
while  the  oleic  acid  is  still  liquid  at  15°  C.  (59°  F.),  so  also  the 
soaps  of  the  former  acids  harden  much  sooner  than  the  oleic 
acid  soap.  The  more  cooled  off  the  soap  is  when  run  into  the 
frames,  the  sooner  the  moment  of  congealing  of  both  soaps 
is  found  to  be  reached,  and  only  an  imperfect  separation  of 
the  same  takes  place,  and  the  coloring  matters,  which  are 
especially  absorbed  by  the  elaidin  soap,  remain  likewise 
divided  in  the  entire  substance.  If  on  the  other  hand  the 
temperature  is  too  high,  then  the  elaidic  soap  impregnated 
with  coloring  matter  precipitates,  and  after  the  stearic  acid 
and  palmitic  acid  soaps  have  crystallized  the  marbling  does 
not  ensue. 

As  marbled  Marseilles  (Castile)  soap  is  now  made  nearly 
everywhere,  and  is  no  longer  confined  to  Marseilles,  we  will 

18 


274  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


note  the  dift'erent  proportions  that  obtain  in  various  locali- 
ties. The  calculations  are  for  about  a  ton  of  fats.  In  Eng- 
land are  used  of — 

Olive  oil,  550  pounds,  or  Olive  oil,        700  pounds. 

Palm  oil,  bleached,  1000  "  Lard,  700 
Tallow,  350        "        Cocoa-nut  oil,200 

Cotton-seed  oil,       350  Tallow,         650  " 

2250  2250 

or, 

Palm-kernel  oil   1500  pounds. 

Sesame  oil   450  " 

Tallow  oil  .       .     '   300 

2250 

In  the  United  States  the  usual  formulas  are — 

Olive  oil,  700  pounds,  or  Palm  oil  (bleached)  1000  pounds 

Ground-nut  oil,  700      "  Cotton-seed  oil,  500 

Lard,  850     "         Tallow,  750  " 

2250  2250 

In  Marseilles  we  have  noticed  that  the  proportions  also  vary 
with  each  manufacturer,  and  the  olive  oil  is  in  greater 
quantity,  though  there  are  in  addition  more  or  less  ground- 
nut oil,  poppy  oil,  hempseed  oil,  sesame  oil,  etc.  etc. 

White  Marseilles  {Castile  soap). — This  truly  tine  soap  may  be 
considered  a  standard  as  to  what  a  pure  soap  should  be,  and 
has  with  the  mottled  Castile  soap  given  character  and  popu- 
larity to  the  soaps  of  France  and  particularly  to  those  of 
Marseilles.  While  the  mottled  soap  cannot  be  well  made  to 
retain  its  proper  marbled  appearance  witli  an  excess  of  water, 
the  white  soap  from  the  difference  in  the  manner  of  manipu- 
lation contains  more  water,  though  nearly  all  impurities 
have  to  be  removed  to  obtain  the  proper  whiteness. 

White  Castile  soap  is  now  made  in  almost  all  countries, 
and  generally  with  the  artificial  sodas,  and  even  in  Marseilles 
these  sodas  are  now  being  used.  Yet  in  some  factories  the 
barilla  is  still  used  as  the  base ;  this  alkali,  containing  a 
certain  percentage  of  potash,  gives  a  plastic  consistency  to 
the  soap  which  has  added  to  its  popularity.  This  effect  is 
now  usually  produced  by  the  addition  of  a  drying  oil,  such 


THE  FABRICATION  OF  SOAPS. 


275. 


as  hempseed,  sesame,  ground-nut,  poppy  or  cotton  seed  oil  to 
the  amount  of  15  to  25  per  cent,  of  the  olive  oil.  These  oils, 
instead  of  being  a  sophistication,  may  be  considered  a  benefit, 
as  they  prevent  the  soap,  which  if  made  with  olive  oil  alone 
becomes  too  hard  in  drying,  from  having  that  undesirable 
property. 

This  soap  is  the  purest  to  be  found  in  commerce,  when  it 
has  been  prepared  and  purified  according  to  the  proper  rules 
of  the  art.  It  is  very  much  used  in  industrial  operations, 
particularly  in  the  bleaching  of  raw  silk.  By  its  extreme 
purity  and  its  nearly  absolute  neutrality,  it  does  not  alter  the 
brilliancy  and  elasticity  of  the  silk,  which  renders  it  supe- 
rior to  all  the  other  kinds  of  soap. 

When  prepared  in  all  its  purity,  it  has  for  its  basis,  with 
the  additions  above  mentioned,  pure  olive  oil,  saponified 
by  caustic  lyes  of  artificial  soft  soda.  These  lyes  are  pre- 
pared in  the  same  manner  as  indicated  for  marbled  soap  ;  but 
as  the  presence  of  salt  would  render  the  soap  less  soluble  in 
water,  the  lyes  must  be  prepared  only  with  soft  soda  free 
from  salt  and  containing  as  little  as  possible  of  sulphuret  of 
sodium.  By  this  precaution  too  much  coloration  of  the  paste 
is  avoided,  and  the  operation  is  much  more  easy. 

In  Belgium,  soda  ash  is  substituted  for  crude  soda  in  the 
preparation  of  the  lyes.  The  soap  thus  made  is  of  a  fine 
pure  white  color.  Thus  by  using  a  colorless  and  a  purer  alkali, 
the  refining  of  the  soap  is  easier,  and  the  amount  obtained 
much  larger  than  with  lyes  made  from  crude  sodas.  This  is 
rational,  and  we  have  seen  soaps  of  olive  oil  thus  prepared, 
which  were  perfectly  white  and  as  pure  as  the  best  Marseilles 
soap. 

Independently  of  the  purity  of  the  alkali,  the  nature  of 
the  oil  emploj^ed  to  prepare  this  soap  exercises  a  remarkable 
influence  on  its  consistency  and  whiteness.  To  obtain  good 
results,  the  whitest  and  most  limpid  oils  must  be  used. 

Experience  proves  that  oils  much  colored  have  the  prop- 
erty of  communicating  their  shade  to  the  soap.  Sometimes 
a  proportion  more  or  less  considerable  of  another  oil  is  mixed 
with  the  olive  oil,  especially  earthnut  oil ;  this  oil,  being 


276  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

* 

white,  has  no  influence  on  the  color  of  the  soap,  but  it  changes 
its  consistency  and  renders  it  more  soluble  and  lathering. 

Pasting.  {Empatage) 

We  suppose  a  saponification  made  with  2250  pounds  of 
oil.  For  this  quantity  use  a  kettle  of  a  capacity  of  from 
1000  to  1250  gallons.  Pour  into  the  kettle  from  175  to  200 
gallons  of  caustic  lye  of  soft  soda  at  8°  to  10°  B.,  which  is 
heated.  When  the  lye  begins  to  boil,  pour  on  the  oil,  and  to 
facilitate  its  combination  with  the  lye,  stir  the  mixture  all 
the  time;  the  stirring  may  be  continued  for  half  an  hour 
after  the  last  portion  of  oil  has  been  introduced. 

This  being  done,  boil  the  mixture.  The  ebullition  must 
be  very  gentle  to  prevent  the  formation  of  too  much  foam. 
If,  notwithstanding  this  precaution,  the  mixture  rises,  the 
heat  is  to  be  slackened,  then  the  ebullition  becomes  less 
rapid,  the  foam  diminishes,  and  the  mixture  boils  regularly; 
but  it  is  essential  to  watch  the  operation,  for  in  the  state  of 
dilatation  the  paste  is  in,  it  would  soon  boil  over.  A  gentle 
ebullition  has  also  for  its  object  to  facilitate  the  combination 
of  the  oil  with  the  lye.  It  is  known  that  the  paste  is  quite 
homogeneous,  when  neither  oil  nor  lye  is  seen  at  the  surface. 

This  result  being  obtained,  pour  into  the  kettle  lyes  at  a 
higher  degree  than  the  first,  at  12°  to  15°  B.,  for  example. 
The  quantity  of  lye  to  be  added  is  not  well  determined,  but 
from  six  to  eight  gallons  may  be  added  without  inconveni- 
ence every  half  hour,  to  take  the  place  of  the  evaporated 
water.  A  slight  excess  of  weak  lye  in  the  pasting  is  not 
injurious,  and  has  the  only  inconvenience  of  making  the 
operation  a  little  longer  and  more  expensive ;  but  as  a  com- 
pensation, the  oil  is  better  saponified,  and  more  completely 
deprived  of  its  coloring  and  mucilaginous  matters,  and  the 
soap  is  finer  and  better. 

After  a  gentle  ebullition  of  eight  or  ten  hours,  the  paste 
becomes  thicker,  and  more  homogeneous.  To  finish,  intro- 
duce 25  to  50  gallons  of  lye  at  5°  B.,  and  after  stirring  for 


THE  FABRICATION  OF  SOAPS. 


277 


half  an  hour,  8top  off  the  heat,  and  proceed  to  the  separation, 
or  cutting  of  the  pan. 

Separation.  {Belargage.) 

This  operation  is  conducted  in  the  same  manner  as  indi- 
cated for  marbled  soap,  that  is,  by  pouring  little  by  little  into 
the  kettle  perfectly  limpid  lyes  of  coction,  ^.  g.,  salted  lyes 
at  20°  to  25°  B.  During  the  introduction  of  the  lye,  a  man 
stirs  the  mass  all  the  time.  It  is  known  that  the  quantity 
of  lye  is  sufficient,  when  the  soap  separates  from  the  lye,  and 
acquires  a  clotted  appearance.  The  more  concentrated  the 
lye,  the  less  the  quantity  to  be  used  to  efiect  the  separation. 

The  operation  being  finished,  cover  the  kettle,  let  it  rest 
five  or  six  hours,  and  then  draw  off  the  exhausted  lye.  If 
not  sufficiently  pure  in  color,  this  cutting  of  the  pan  can  be 
repeated,  when  proceed  to  the  coction. 

Clear-Boiling,  or  Coction. 

1.  First  Service  of  Lye. — To  begin  the  operation,  pour  at 
first  into  the  kettle  from  125  to  150  gallons  of  soft  lye,  at 
15°  to  18°  B.,  heat  gently,  and  when  the  soap  is  very  warm, 
stop  oft'  the  heat.  This  done,  the  soap  is  briskly  stirred  for 
three-quarters  of  an  hour  or  an  hour.  By  stirring  thus,  the 
soap  is  brought  into  contact  with  the  lye,  and  by  combining 
with  the  alkali  it  acquires  more  consistency,  at  the  same 
time  that  it  is  deprived  of  the  larger  portion  of  the  foreign 
salts  that  it  has  absorbed  during  the  saponification  and  sepa- 
ration. 

Eendered  purer  by  this  first  washing,  the  soap  is  more  fit 
to  combine  with  the  concentrated  lyes  which  bring  it  to  the 
proper  point  to  be  purified.  After  a  settling  of  a  few  hours 
the  lye  is  drawn  off. 

2.  Second  Service  of  Lye. — For  this  second  service,  pour 
into  the  kettle  100  gallons  of  caustic  and  concentrated  lye, 
at  22°  to  25°  B.    Boil  the  mixture  gently  for  eight  or  ten 


278  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


hours,  adding  every  hour  six  gallons  of  pure  lye  to  take  the 
place  of  the  evaporated  water. 

During  the  ebullition,  a  very  abundant  foam  is  formed  on 
the  surface  of  the  soap,  but  its  development  is  moderated  by 
slacking  the  heat  or  beating  it  down  with  the  stirrers,  when 
during  the  ebullition  the  soap  is  entirely  granulated,  and 
floats  in  the  lye.  By  pressing  it  between  the  fingers,  it  is 
found  to  have  more  consistency,  but  it  is  yet  greasy,  because 
it  is  not  yet  completely  saturated  with  alkali.  To  bring  it 
to  the  state  of  saturation,  the  heat  is  stopped  off,  and  the 
mixture  left  to  settle  for  a  few  hours;  then  a  third  and  last 
service  of  new  lye  is  given. 

3.  Third  Service  of  Lye. — For  this  service,  use  a  new  lye 
marking  28°  or  30°  B.  Pour  into  the  kettle  110  gallons  of 
the  lye  and  then  heat.  After  an  ebullition  of  five  or  six  hours, 
the  grain  of  the  soap  is  well  developed,  and  when  pressed  be- 
tween the  fingers  forms  hard  and  dry  scales.  Continue  the 
ebullition  for  a  few  hours,  and  when  the  soap  is  saturated, 
the  foam  which  covered  it  disappears  almost  entirely,  and  that 
which  is  left  is  very  light  and  white.  If  the  oil  used  is  of  a 
good  quality,  the  kettle  emits  an  odor  somewhat  similar  to 
that  of  the  violet;  the  heat  is  stopped  ott",  and  after  resting  for 
a  few  hours,  the  lye  is  drawn  off.  This  lye,  by  being  passed 
over  a  mixture  of  soda  and  lime  half  exhausted,  becomes 
clear,  limpid,  and  caustic,  and  may  be  used  anew  to  separate 
the  soap  in  a  subsequent  operation. 

When  thus  saturated,  this  soap  contains  only  16  per  cent, 
of  water,  and  is  very  alkaline  and  caustic.  Its  coloration 
is  due  to  the  use  of  crude  sodas,  and  especially  to  the  pres- 
ence of  the  sulphurets  of  soda  and  iron,  always  existing  in 
these  sodas,  which  combine  with  the  oxide  of  iron,  also  ex- 
isting in  them,  and  give  rise  to  a  sulphuret  of  iron  which 
colors  the  soap.  To  refine  it,  it  is  necessary  to  submit  it  to 
a  last  operation  called  fitting  and  by  the  French  soapmakers 
liquidation. 


THE  FABRICATION  OF  SOAPS. 


279 


Fitting. 

To  transform  into  a  pure  white  soap  the  mass  of  soap  which 
has  a  bluish-gray  color,  it  has  to  be  dissolved  by  degrees  in 
weak  lyes  with  the  aid  of  heat.  To  begin,  pour  into  the 
kettle  from  125  to  150  gallons  of  soft  lye  at  8°  to  10°  B.  and 
apply  heat.  When  the  soap  is  very  warm,  stir  it  briskly. 
0nder  the  influence  of  the  heat,  of  the  lyes,  and  the  stirring, 
the  grain  dilates,  softens,  and  looks  as  if  half  melted  in  the 
lye.  When  in  this  state  slacken  the  heat,  and  after  a  few 
hours'  rest,  draw  off  the  lye. 

By  this  first  operation,  the  paste  begins  to  be  deprived  of 
the  coloring  matter  and  the  excess  of  alkali  it  contains,  but 
it  is  still  caustic.  To  complete  its  refining,  pour  into  the 
kettle  from  50  to  60  gallons  of  soft  lye  at  5°  or  6°  B.  and 
heat  gently,  stirring  the  paste  all  the  time  from  the  bottom 
to  the  surface.  By  agitation  and  heat,  the  paste  becomes 
more  and  more  fluid,  and  is  yet  separate  from  the  lye.  As 
its  refining  can  take  place  only  when  completely  liquefied,  to 
obtain  this  result,  add  from  time  to  time  a  few  pailfuls  of 
lye  at  2°  or  3°  B.,  continuing  the  heat  and  the  stirring. 
When  it  has  become  fluid,  and  the  liquid,  brought  to  the  sur- 
face by  the  stirring,  has  a  blackish  color  and  is  viscous,  the 
operation  is  finished,  because  the  coloration  is  due  to  the 
precipitation  of  the  alumino-ferruginous  soap — and  the  vis- 
cosity to  the  complete  liquefaction  of  all  the  parts  of  the 
paste. 

When  in  this  state,  stop  off  the  heat,  cover  the  kettle  and 
surround  it  with  woollen  blankets,  so  as  to  retain  the  heat 
as  long  as  possible.  By  resting  and  the  heat  of  the  mixture, 
the  metallic  soap,  i.  e.,  iron  oxide  soap,  and  the  excess  of 
alkali  precipitate  to  the  bottom  of  the  kettle,  as  well  as  the 
excess  of  weak  lyes  used  in  this  operation. 

After  a  rest  of  36  to  40  hours,  uncover  the  kettle,  and 
take  off  carefully  the  scum  formed  on  the  surface.  Dip  off 
the  soap  with  large  iron  ladles  into  frames.  When  the  black 
soap  begins  to  appear,  the  operator  must  be  careful  not  to 


280 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


disturb  it,  since  its  mixture  with  the  white  soap  would  render 
it  less  neutral  and  less  pure.  When  all  the  soap  is  in  the 
frames  it  is  well  stirred  so  as  to  have  it  perfectly  homoge- 
neous ;  if  not  stirred  it  would  present  veins  and  even  spots 
of  color. 

When  the  soap  is  completely  solidified  in  the  frames,  it  is 
flattened  by  beating  it  with  large  wooden  beaters.  This 
operation  renders  the  soap  more  compact  and  heavier,  it  is 
useful  also  to  fill  the  vacant  spaces  due  to  the  air  in  the  soap. 
In  conclusion,  the  beating  of  the  soap  fulfils  two  essential 
conditions :  1.  It  increases  its  specific  gravity  ;  2.  It  destroys 
its  porosity. 

A  few  days  after  the  frames  are  uncovered,  and  the  soap  is 
divided  into  bars  or  cakes  by  the  usual  methods. 

Recently  manufactured,  this  soap  is  always  a  little  soft. 
To  give  it  the  firm  consistency  required  in  commerce,  it  is 
exposed  for  a  few  days  to  the  air  in  the  drying-room,  then  it 
becomes  solid  enough  to  be  packed  in  boxes.  Exposure  to 
the  sun,  or  to  too  elevated  a  temperature,  must  be  avoided, 
for  heat  always  communicates  to  it  a  more  or  less  yellow 
shade.  Another  method  of  hardening  is  to  dip  the  bars  of 
soap  into  a  very  strong  lye,  which  hardens  the  surface  and 
makes  them  the  sooner  marketable. 

When  the  soap  is  not  to  be  sold  immediately,  the  boxes 
containing  it  are  stored  in  a  cellar.  A  few  weeks  after  it 
will  have  acquired  the  whiteness  and  solidity  which  dis- 
tinguish fine  Marseilles  soap. 

Well-prepared  White  Soap  from  Olive  Oil  constitutes,  as  we 
have  before  said,  the  purest  soap  of  commerce.  One  hundred 
parts  of  this  soap  are  composed  of: — 

Fatty  acid3  50.20 

Pure  soda  4.60 

Water  45.20 

100.00 

Ey  operating  under  favorable  circumstances,  that  is,  using 
the  purest  and  whitest  olive  oil,  and  the  best  quality  of  arti- 
ficial soda,  the  2250  pounds  of  oil  will  give : — 


THE  FABRICATION  OF  SOAPS. 


281 


Soap  of  scum 
Pure  white  soap 
Black  soap  . 


157  to  225 
2925  to  3040 
675  to  790 


We  see  by  these  numbers  that  2250  pounds  of  oil  give  as 
a  maximum  3040  pounds  of  soap,  or  135  pounds  of  soap  for 
every  100  pounds  of  oih  The  black  soap  left  in  the  kettle 
as  a  residuum  of  the  operation  is  separated,  while  warm, 
from  the  weak  lyes  with  which  it  is  combined,  by  means  of 
salted  lyes  at  20°  to  25°  B.  It  is  then  run  into  a  frame  and 
allowed  to  cooL  In  a  regular  mode  of  working,  this  black 
soap  is  utilized  in  a  new  operation,  and  gives  by  refining 
a  new  quantity  of  pure  soap  by  the  precipitation  of  the 
coloring  matters  it  contains.  This  method  is  not  without 
inconvenien-ces,  because  this  mass  of  black  soap  introduced 
into  each  new  coction  impairs  the  whiteness  and  purity  of 
the  soap.  It  would  be  more  rational  to  use  this  residuum  in 
the  fabrication  of  marbled  soaps  which  are  not  required  to 
have  the  purity  of  color  of  the  w^hite  soap. 

The  formulae  for  the  marbled  soap  may  apply  to  this  soap, 
though  there  should  always  be  a  large  percentage  of  olive  oil. 

White  Castile  {Marseilles)  Soap,  when  made  in  countries 
where  olive  oil  is  not  abundant  and  is  high  priced,  is  now 
usually  made  with  but  a  small  percentage  of  that  expensive 
oil.  Thus  in  England,  Germany,  and  the  United  States  are 
used  bleached  palm  oil,  palm-kernel  oil,  ground-nut  oil,  poppy 
oil,  cotton-seed  and  hemp-seed  oil,  tallow  oil  or  olein,  tallow 
in  combinations.  Having  a  due  regard  to  their  purity  and 
whiteness  we  give  some  suggestions  of  proportions : — 

Olive  oil  40  parts.  Olive  oil  30  parts. 

Ground-nut  oil     .    .    30     "      Lard  30  " 

Tallow  30     "      Palm-kernel  oil    .    .    40  " 

Olive  oil  30  parts.  Palm  oil  (bleached)  .    50  parts. 

Cotton-seed  oil .    .    .    3t)    "      Sesame  oil  20  " 

Tallow  oil    ....    40    "      Tallow  30  " 


The  fabrication  of  this  soap  is  in  general  the  same  as 
that  of  the  olive  oil  soaps.    When  tallow  is  used  it  is  freed 


Tallow  Soap.    (Curd  Soap.) 


282  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


from  all  admixtures  and  impurities  by  melting  and  deposit- 
ing. Thus  prepared,  the  soap  may  very  well  be  finished  in 
one  boiling.  When  impure  tallow  of  a  brown  color  is  used, 
it  becomes  necessary  to  finish  the  soap  upon  two  or  more 
w^aters.  In  this  case  also  a  lye  of  2°  B.  at  the  most  6  per 
cent,  soda  is  used,  which  should  be  caustic  and  free  from 
culinary  salt.  Since  the  tallow  consists  chiefly  of  stearin 
and  olein  with  but  little  palmitin  glyceryl  oxide,  the  amount 
of  materials  necessary  for  saponification  is  calculated  accord- 
ing to  the  heretofore  mentioned  equivalents  of  tallow,  to  wit, 
887.0.  According  to  this  there  are  100  kilog.  (220  lbs.)  tallow 
corresponding  to  10.5  kilog.  (23.1  lbs.)  of  soda  (anhydrous), 
so  that  for  a  boiling  of  2000  kilog.  (4400  lbs.)  210  kilog.  (462 
lbs.)  of  soda  are  required,  which  in  four  portions  of  lye  are 
separately  brought  into  use.  Since  the  first  portion,  or  the 
fourth  part  =  52.5  kilog.  (115.5  lbs.)  is  to  be  taken  not  above 
6  per  cent,  lye,  and  whereas  in  20  litres  (5.29  gallons)  of  such 
a  lye  1.31  kilog.  (2.88  lbs.)  soda  are  contained,  there  would 

have  to  be  taken  thereof  ^^-^^^^     goO  litres  (211  gallons). 

The  lye  is  placed  in  the  kettle,  heated  to  boiling,  and  then 
the  tallow  is  added.  The  melting  fat  mixes  immediately 
with  the  lye  to  a  milky  fluid  wherein  fat  and  lye  can  no 
longer  be  plainly  discovered,  although  a  real  chemical  com- 
bination does  not  yet  ensue.  The  entire  mass  soon  begins 
to  boil,  and  at  first  it  froths  very  much,  but  gradually  begins 
to  clear,  becomes  more  translucent  and  also  thicker.  But  if 
an  open  fire  be  used,  the  heat  must  be  diminished,  to  avoid 
burning.  The  entire  mass  becomes  turned  into  a  translucent 
lustrous  liquid,  the  soap  paste  runs  from  the  spatula  in  fine 
threads,  the  lye  and  fat  of  which  upon  the  paddle  no  longer 
appear  separate. 

Sometimes  it  takes  very  long  before  the  fat  and  lye  unite 
into  a  paste.    Usually  the  reason  for  this  is  found : — 

1.  In  a  too  concentrated  Xye.  The  mass  boils  at  starts, 
very  violently,  since  the  lye,  because  it  cannot  mix  with  the 
fat  on  account  of  its  concentration,  settles  upon  the  bottom, 


THE  FABRICATION  OF  SOAPS. 


283 


becomes  strongly  heated  and  breaks  with  violence,  the  fatty 
mass  floating  above.  This  fault  is  remedied  by  weakening 
the  lye  with  water,  and  constantly  stirring  the  mass.  Tlie 
production  of  some  soap  causes  a  corresponding  weakening  of 
the  lye  as  a  consequence,  and  the  process  again  proceeds  in  a 
regular  way.  2.  In  a  not  sufficiently  caustic  lye.  This  is 
discerned  when  by  testing  the  lye  with  acid  it  foams  up  very 
strongly.  A  gradual  addition  of  caustic  lye  remedies  this 
defect.  3.  In  too  much  lye.  Here  we  may  help  ourselves  by 
the  addition  of  fat,  or,  still  better,  by  an  addition  of  scrap- 
soap. 

After  the  first  quarter  of  the  soda  has  united  with  the  fat 
or  becomes  pasted,  the  second  quarter  is  added,  for  which  a 
strong  lye  15°  to  18°  B.  will  best  serve.  20  litres  (5.29  gal- 
lons) of  such  a  lye  contain  about  2  kilog.  (4.40  lbs.)  soda,  so 
we  must  therefore  to  reach  52.5  kilog.  (115.5  lbs.)  lye  take  of 
this  lye  26.25  x  20,  that  is  525  litres  (139  gallons)  lye. 

All  further  operations  are  entirely  the  same  as  in  the  case 
of  Marseilles  soap. 

The  soap  must  be  run  hot  into  the  frames,  and  for  the  first 
two  days  be  well  covered  with  cloths.  On  the  second  day  it 
is  cut  on  the  edges  and  pressed  or  stamped  down,  to  avoid  its 
becoming  hollow  in  the  centre  by  shrinking. 

The  touch  or  alkali  of  the  sub-lye  is  removed  by  boiling 
it  in  a  sufficient  quantity  of  oleic  acid,  which  also  absorbs  the 
carbonate  of  soda.  Instead  of  oleic  acid  another  fat  can  be  ap- 
plied, but  the  fat  in  this  case  must  be  previously  made  pasty. 
This  is  done  by  means  of  a  small  portion  of  weak  caustic  lye. 
The  cutting  of  the  pan  is  now  performed  with  the  still  caustic 
sub-lye  and  adding  ad  libitum  so  much  fat  and  salt  to  it  until 
all  trace  of  a  touch  in  the  lye  has  vanished.  The  last  boiling 
is  kept  and  applied  to  the  next  boiling  of  soap. 

Many  manufacturers  use  rosin  for  the  removal  of  the  touch, 
that  is,  for  regaining  the  soda  contained  in  the  sub-lye,  w^hich 
is  entirely  rational,  because  the  rosin  combines  as  well  with 
the  carbonate  as  with  the  caustic  soda.  The  rosin  soap  is  to 
be,  as  usual,  separated  from  the  salt  (cutting  up  of  the  pan) 
and  afterwards  added  to  another  soap  boiled  in  fat.    It  is 


284  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


self-evident  that  every  other  soap  may  be  thus  treated  whose 
Bub-lye  still  shows  traces  of  a  touch  or  presence  of  alkali. 

Palm  Soap. 

In  saponifying  palm  oil  it  is  customary  to  mix  it  with 
other  fats  and  oils,  either  in  its  natural  state,  or  deprived  of 
its  strong  yellow  color  which  will  remain  unchanged  in  the 
soap  and  will  stain  linen  and  other  fabrics.  The  process  of 
decolorizing  the  oils  has  been  fully  described  elsewhere.  In 
England  many  of  the  soaps  for  domestic  uses  are  made  of 
this  oil,  though  usually  in  combination  with  tallow,  cocoa- 
nut  oil,  and  rosin,  while  in  other  countries  where  the  oil  is 
not  so  abundant  it  is  principally  used  for  toilet  soaps,  bat 
rarely  by  itself. 

A  jpure  palm-oil  socqo  we  will  take  for  example :  To  1000 
kilog.  (2200  lbs.)  pure  palm  oil  110  kilog.  (242  lbs.)  soda  are 
needed ;  this  first,  stronger  lye  must  therefore  contain  55  kilog. 
(121  lbs.)  soda ;  lye  of  18°  B.  is  used,  and,  whereas  such  a  lye  con- 
tains in  the  litre  0.161  kilog.  (0.35  lb.),  we  must  for  55  kilog. 
(121  lbs.)  soda  take  342  litres  (90.3  gallons)  of  lye.  As  soon 
as  the  fat  combines  with  this  lye,  there  should  be  added  gradu- 
ally 360  litres  (95  gallons)  of  a  20°  B.  lye  having  a  tolerably 
strong  touch.  Since  the  palm  oil  often  contains  a  consider- 
able quantity  of  free  palmitic  acid,  a  certain  quantity  of 
carbonate  of  soda  may  be  applied  at  once,  and  when  this 
becomes  saturated  with  the  palmitin,  then  the  rest  is  to  be 
saponified  with  pure  caustic  lye.  This  is,  however,  not  the 
same  as  if  a  carbonated  soda  lye  were  to  be  used.  In  this 
case,  the  intention  would  not  be  fulfilled,  since  the  free  pal- 
mitic acid  absorbs  at  first  the  soda,  while  the  carbonate  of 
soda  remains  uncombined.  The  soap  having  finished  boiling 
is  separated  by  culinary  salt,  boiled  until  all  froth  disappears, 
gently  ground  or  fitted,  and  the  soap  is  run  hot  into  the 
frames,  where  it  is  well  covered  and  left  to  stand.  In  this 
case  too,  the  rims  of  the  soap  in  the  frames  are  cut  on  the 
second  day,  and  the  soap  pushed  together. 

Palm-oil  soap  is  always  hard  and  brittle,  and  to  divest  it 


THE  FABRICATION  OF  SOAPS. 


285 


of  this  peculiarity,  which  is  by  no  means  desirable,  5  per  cent, 
of  the  soda  is  substituted  by  potash,  which  makes  it  more 
plastic. 

We  submit  a  few  of  the  combinations  in  vogue  for  palm 
soap. 


Palm  oil    .    .  . 

.    50  parts. 

Palm  oil    .    .  . 

.    85  parts. 

Tallow      .    .  . 

.    30  " 

Cotton -seed  oil  . 

.    35  " 

Resin  .... 

.    20  " 

Pure  tallow  .  . 

.    30  " 

Palm  oil    .    .  . 

.    40  parts. 

Palm  oil    .    .  . 

.    60  parts. 

Tallow      .    .  . 

.    30  " 

Tallow     .    .  . 

.    20  " 

Cocoa-nut  oil 

.    30  " 

Cocoa-nut  oil .  . 

.    20  " 

RosiN  Soap.    (Yellow  Soap.) 

Eosin  in  soap  may  be  styled  an  ameliorator,  for,  though  in 
itself  it  will  not  form  with  alkali  a  useful  soap,  yet  combined 
with  fats,  or  when  saponified  added  to  other  soaps  made  with 
the  fatty  bodies,  it  counts  as  so  much  grease,  and  contributes 
the  popular  qualities  of  being  readily  soluble  and  forming  a 
copious  lather  when  used  for  laundry  and  other  domestic 
purposes. 

The  methods  for  forming  this  soap  are  various :  Either  the 
rosin  is  saponified  separately,  or  it  is  melted  with  the  grease 
and  boiled  with  the  lyes.  The  latter  is  the  usual  mode  in 
England,  where  is  also  added  to  the  better  qualities  of  rosin 
soaps  a  portion  of  palm  oil,  which  tends  to  improve  both 
their  odor  and  color. 

Rosins  in  the  United  States  are  usually  prepared  for  the 
soap  boiler  at  the  place  of  their  production,  and  are  of  difi^'er- 
ent  qualities  depending  upon  their  color ;  of  course  the  lighter 
and  clearer  in  color  the  rosin  is  the  better  will  be  the  quality 
and  appearance  of  the  soap.  Yet  it  may  be  that  the  rosin 
at  hand  is  dark  and  contains  many  impurities.  If  so,  it 
is  necessary  to  submit  it  to  a  purification,  which  is  usually 
done  by  boiling  it  with  a  solution  of  common  salt,  when  the 
impurities  and  much  of  its  color  are  precipitated  with  the 
salt  water.  This  is  often  repeated  a  second  or  a  third  time 
to  insure  a  bright  color. 


286 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Cocoa-nut  oil  is  often  added  to  rosin  soaps,  and  is  said  to 
simplify  the  process  and  take  less  boiling;  this  oil  moreover 
making  the  soap  more  solid. 

The  usual  formula  is: — 


The  usual  method  used  in  England  is,  to  charge  the  pan 
with  2000  pounds  of  tallow  or  soap  grease,  about  600  pounds 
of  rosin,  and  150  to  1.75  gallons  of  soda  lye  marking  10° 
to  20°  B. ;  and,  when  the  whole  is  melted  and  thoroughly 
combined,  heat  up  the  mixture  to  ebullition,  being  careful  to 
stir  all  the  while  to  prevent  the  adherence  of  the  rosin  to 
the  bottom  and  sides  of  the  pan.  If  the  mass  seems  disposed 
to  intumesce  or  swell,  the  fire  must  be  lessened.  This  boil- 
ing should  continue  but  two  or  three  hours,  because  of  the 
facility  with  which  the  union  of  the  fat  and  alkali  is  effected. 
After  six  hours'  repose,  the  exhausted  lye  is  drawn  off,  and 
fresh  is  substituted,  and  the  whole  is  again  boiled  for  three 
hours  more.  Another  repose  of  six  hours  is  allowed,  and  the 
spent  lye  is  again  drawn  off  and  renewed  by  fresh  additions  ; 
the  boilings  are  thus  continued  until  the  soap  shall  have  ac- 
quired consistency — a  fact  determined  by  taking  a  sample, 
and  when  cool,  squeezing  it  between  the  thumb  and  finger. 
If  hard,  thin  scales  are  formed,  it  is  finished,  or  nearly  so; 
if  greasy,  clammy,  and  soft,  it  is,  on  the  contrary,  not  perfect, 
and  must  have  more  lye,  and  another  boiling.  In  the  first 
case,  give  a  brisk  boiling  to  the  paste,  and  then  put  out  the 
fire.  Cool  the  soap  by  adding  three  buckets  of  weak  lye,  and 
two  hours  after,  draw  oflt' the  sub-lye.  ^^ext  throw  in  six  or 
eight  buckets  of  water  and  boil  briskly,  stirring  the  mixture 
until  the  soap  is  melted ;  then,  with  a  wooden  spatula,  take 
a  little  of  the  boiling  paste,  hold  it  up  and  observe  whether 
it  runs  from  the  lye  clear;  if  it  does,  add  water  to  the  pan, 
and  continue  the  boiling.  If  it  does  not  run  from  the  lye, 
too  much  water  has  been  added  already,  and  there  must  then 


Palm  oil 
Cocoa-nut  oil 
Tallow  " 
Rosin  " 


20  parts. 


20 
80 

30  " 


THE  FABRICATION  OF  SOAPS. 


287 


be  poured  in  half  a  bucketful  of  strong  solution  of  common 
salt. 

The  most  delicate  part  of  the  operation  is  that  of  finish- 
ing or  fitting,  and  should,  therefore,  command  the  particular 
attention  of  the  workman.  If  the  fitting  is  perfect,  the  soap 
will,  when  the  spatula  is  held  obliquelj^not  run  ofi:',  but  shake 
and  disperse  tremulously  like  jelly.  It  is  then  that  the  fire 
ma}^  be  withdrawn,  and  the  soap  be  regarded  as  finished. 

If  it  is  desired  to  give  a  better  color  to  this  soap,  about 
20  pounds  of  palm  oil  may  be  added  before  finishing;  and 
after  two  days  it  must  be  run  into  the  frames,  whence,  after 
a  week  or  less,  it  should  be  taken  and  cut  into  bars. 

When  cocoa-nut  oil  is  added,  it  is  best  to  saponify  sepa- 
rately with  a  strong  lye,  and  add  at  the  finish. 

By  a  still  more  simple  process,  the  English  now  prepare 
this  soap  as  rapidly  as  economically. 


Caustic  lye  of  soda  ash  at  25^     .       .       .    175  gallons. 

The  whole  is  introduced  into  a  large  Papin's  digester,  and 
the  mixture  submitted  for  one  hour  to  ebullition  under  pres- 
sure, at  a  temperature  of  122.2°  C.  (252°  F.).  After  this 
time  the  soap  is  finished  and  run  into  the  frames. 

This  seems  to  be  all  that  is  necessary  to  say  about  these 
useful  soaps.  Of  course  if  a  soap  is  wanted  by  the  old  methods, 
we  can  but  refer  to  the  tallow  soap,  adding  the  rosin  soap 
which  has  been  made  separately. 

Resinous  Grain  Soap  and  Turpentine  Soap. 

The  first  is  a  dark  brown  soap,  which  with  100  parts  fat 
are  combined  80  to  90  parts  brown  rosin.  Turpentine  soap 
possesses  a  light-yellow  color,  and  is  obtained  by  saponi- 
fying 100  parts  of  fat  with  25  to  30  parts  light  rosin.  For 
the  fat  sometimes  tallow  or  palm  oil  alone  is  used,  or  in  con- 
nection with  olein,  i,  e.,  oleic  acid.    In  the  latter  case  an 


Take- 


White  tallow 
Palm  oil 
Powdered  rosin 


800  pounds. 
200  " 
400 


288  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


addition  of  about  5  per  cent,  cocoa  oil  is  made  ;  the  soap  there- 
by attaining  the  property  of  frothing  very  well.  The  rosin- 
grain  soap  is  always  produced  with  very  caustic  lye,  which 
is  best  prepared  by  dissolving  caustic  soda  in  water.  The 
rosin  must  be  well  pulverized,  before  it  is  placed  in  the  ket- 
tle, and  immediately  well  stirred,  as  the  matter  easily  ascends 
and  runs  together  into  lumps,  which  can  only  be  re-separated 
with  difficulty.  A  preliminary  boiling  in  this  case  is  not 
necessary,  though  the  lyes  should  be  added  in  portions,  the 
boiling  being  well  sustained,  care  being  taken  to  add  weak 
lyes  or  water  to  make  up  for  evaporation.  When  the  soap  has 
assumed  the  true  gelatinous  appearance,  it  can  be  separated 
from  its  superfluous  water  with  salt,  and  afterwards  fitted 
or  ground  to  bring  it  to  the  proper  consistency.  This  is 
often  done  with  a  solution  of  carbonate  of  soda. 

Olein  Soap,  Oleic  Acid  Soap,  Elaidin  Soap. 

Under  these  various  names  is  the  soap  made  from  oleic 
acid  (commonly  known  as  "  red  oil")  called.  This  acid,  being 
a  by-product  in  the  making  of  stearic  acid,  stearin,  and 
glycerine  by  means  of  lime,  sulphuric  acid,  etc.,  though 
it  is  limpid  at  ordinary  temperatures,  contains  some  stearin 
and  palmitin,  but  no  glycerine,  and  as  it  is  generally  low  in 
cost,  it  makes  an  economical  and  useful  soap,  either  by  itself 
or  in  combination  with  other  greases,  as  tallows,  cotton-seed 
oil,  rosin,  etc. 

There  are  numerous  modes  of  saponifying  this  valuable 
sebacic  acid,  and  it  is  difficult  to  say  which  produces  the  best 
soap,  yet  we  must  confess  to  a  preference  for  that  made  by 
the  regular  process  of  boiling  as  certainly  the  most  reliable. 
We  will,  however,  give  what  we  consider  the  best  processes 
for  some  of  the  others. 

Owing  to  the  presence  of  some  free  sulphuric  acid  and  other 
impurities,  the  oleic  acid  requires  generally  more  alkali  for 
its  saponification,  though  it  need  not  be  entirely  free  from 
other  salts  or  carbonic  acid.  Thus  owing  to  its  easy  saponi- 
fication it  is  sometimes  made  in  an  extemporaneous  way  by 


THE  FABRICATION  OF  SOAPS. 


289 


simply  adding  the  crystalline  carbonate  of  soda  to  the  olein, 
putting  into  an  air-tight  vessel  having  a  stirrer,  and  under 
the  pressure  and  agitation  causing  a  rapid  admixture,  the 
water  of  crystallization  being  in  sufficient  quantity  to  form 
the  soap.  This  process  requires  a  close  calculation  of  the 
several  quantities  and  some  experience  to  produce  a  good  and 
uniform  product. 

Being  a  cheap  material  and  comparatively  pure,  it  can  be 
economically  combined  with  other  greases,  such  as  kitchen 
and  bone  fats  and  other  refuse  greases.  It  also  makes  one 
of  the  most  useful  soft  soaps  for  manufactures. 

For  making  a  pure  olein  soap  in  a  large  way  we  will  take 
say  6750  lbs.  of  oleic  acid.  The  saponification  is  elFected  in 
a  kettle  of  a  capacity  of  1870  to  2000  gallons,  into  which  the 
oleic  acid  is  introduced  and  melted  with  the  help  of  a  gentle 
heat.  The  acid  being  completely  liquefied,  pour  into  the 
kettle  125  gallons  of  new  lye  at  25°,  and  250  gallons  of  lye 
of  coction  perfectly  limpid  at  25°  to  30°  B.  It  often  hap- 
pens that  by  the  reaction  of  the  lyes  on  the  oleic  acid,  the 
mixture  considerably  thickens  and  forms  a  compact  mass. 
This  eftect  is  due  to  the  spontaneous  formation  of  stearate 
and  margarate  of  soda,  but  as  the  heat  increases,  the  mixture 
becomes  clear,  the  grains  gradually  disappear  and  the  mass 
becomes  fluid. 

Continue  to  keep  up  a  gentle  heat,  and  when  the  ebulli- 
tion begins  a  considerable  quantity  of  foam  is  developed  on 
the  surface  of  the  soap.  This  effervescence  is  moderated 
either  by  slacking  the  heat,  or  by  stirring  all  the  time,  or  by 
pouring  a  few  pails  of  cold  water  into  the  kettle.  This 
rapid  reaction  is  due  to  the  action  of  the  carbonate  of  soda, 
which,  in  contact  with  the  oleic  acid,  abandons  its  carbonic 
acid.  But  this  effect  would  not  take  place  if  the  lyes  used 
were  entirely  caustic.  When  this  first  effervescence  has 
ceased,  increase  the  heat,  and  continue  to  boil  quickly ;  care 
being  taken  to  stir  all  the  time.  By  continuing  the  ebulli- 
tion, the  lye  becomes  more  and  more  concentrated  by  the 
evaporation.  The  nature  of  the  paste  is  modified,  and  by  a 
progressive  saturation  with  alkali,  it  acquires  consistency. 
19 


290 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


However,  when  the  pasting  is  finished,  the  paste  has  not  the 
consistency  of  the  ordinary  soaps,  which  difference  is  ex- 
plained by  the  nature  of  the  oil  on  which  we  operate — this 
oleic  acid  being  almost  entirely  formed  of  the  oily  and  liquid 
part  of  the  tallows,  that  is,  of  the  part  the  least  apt  to  form 
hard  soaps.  It  is  only  after  the  paste  is  completely  saturated 
with  alkali  that  it  forms  a  very  consistent  soap.  This  re- 
mark may  be  applied,  at  least  generally,  to  every  fatty  or 
oily  substance  in  which  olein  predominates. 

The  time  for  the  first  operation,  on  6700  lbs.  of  material, 
varies  from  ten  to  fifteen  hours.  It  is  ascertained  that  the 
pasting  is  terminated,  when  the  grains  of  soap  formed  at  the 
beginning  of  the  operation  are  entirely  dissolved ;  then  the 
heat  is  stopped  ofi:',  and  after  resting  ten  or  twelve  hours  the 
lye  is  drawn  off. 

Observations. — The  pasting  being  finished,  it  is  important 
to  let  the  mass  rest  for  ten  or  twelve  hours,  to  permit  the 
lye  not  combined  with  the  soap  to  separate  as  completely  as 
possible.  If  much  of  it  is  left  in  the  paste,  it  will  be  trou- 
blesome in  the  coction,  for  two  reasons  :  first,  on  account  of 
the  great  quantity  of  neutral  salts  it  contains,  and  which 
would  render  the  soap  less  hard ;  then  because  it  would 
weaken  the  degree  of  the  new  lyes  of  the  first  service,  in 
such  a  manner  that  the  action  of  these  lyes  on  the  olein 
would  be  less  efficacious  than  if  the  operation  had  been  con- 
ducted with  a  paste  less  saturated  with  neutral  salts. 

Whilst  colored,  this  sub-lye  is  generally  limpid ;  but  as  it 
marks  from  18°  to  22°  B.,  it  has  to  be  reduced  to  8°  or  lO'^ 
by  the  addition  of  water.  It  is  then  left  to  settle  for  a  few 
days,  and  passed  through  an  old  residuum  of  exhausted  soda 
ash  and  lime.  For  6700  pounds  of  oleic  acid,  the  quantity 
of  lyes  drawn  ofi'  after  ten  or  twelve  hours'  rest,  amounts  to 
175  to  200  gallons,  and,  though  marking  from  18°  to  20°  B., 
containing  very  little  useful  alkali  but  many  other  salts. 

The  coction  is  effected  with  new  caustic  and  concentrated 
lyes  of  soda  ash.  Two  services  are  generally  sufficient  to  bring 
the  soap  to  the  point  of  complete  saturation. 


THE  FABRICATION  OF  SOAPS. 


291 


First  Service  of  Lye. — All  the  Ije  of  the  first  operation  being 
drawn  off,  pour  into  the  kettle  from  225  to  250  gallons  of 
fresh  Ije  at  27°  or  28°  B.  Heat  and  keep  the  mixture  to 
boiling.  At  the  beginning  the  ebullition  must  be  gentle; 
too  active  boiling  would  dilate  the  mass  considerably,  or 
cause  the  soap  to  stick  to  the  bottom  of  the  kettle. 

Thus,  for  the  first  hours  the  kettle  must  boil  gently.  It  is 
true  the  soap  is  separated  from  the  lye  but  slightly ;  its  grain 
is  not  completely  formed,  and  it  is  yet  soft, flaccid,  and  dilated ; 
but  it  is  proper  to  have  it  so,  for  in  this  half-viscous  state, 
the  action  of  the  lye  on  the  oleic  acid  is  more  direct  and  more 
rapid  than  if  the  grain  of  the  soap  were  prematurely  formed. 

During  all  this  first  stage  of  the  operation  it  is  very  im- 
portant, we  repeat,  to  boil  gently  and  uniformly.  A  more 
complete  and  equal  saturation  of  the  oleic  acid  by  the  lye 
is  obtained.  The  formation  of  too  much  foam  is  also  to  be 
avoided.  Later — that  is,  after  five  or  six  hours  of  ebullition 
— the  heat  is  progressively  increased;  by  evaporation  the 
lye  concentrates,  and  the  grain  of  the  soap  becomes  larger 
and  firmer.  While  the  lyes  do  not  separate  as  completely  as 
in  the  first  service,  it  is  easy  to  see  that  the  soap  is  not  so 
viscous,  and  is  less  greasy  than  at  the  beginning  of  the  op- 
eration. To  render  the  separation  more  complete,  and  to 
compensate  for  the  loss  due  to  the  evaporation,  add  every 
hour,  for  the  first  six  hours,  from  ten  to  twelve  gallons  of 
new  lye  at  27°  or  25°  B.;  add  also,  towards  the  end  of  the 
first  service,  fifteen  gallons  of  salted  water  at  25°  B.  This 
addition  of  salted  water  contracts  the  soap,  and  facilitates 
its  separation  from  the  excess  of  lye  with  which  it  is  mixed. 

Lastly,  after  twelve  or  fifteen  hours  of  continual  ebullition 
turn  ofi*  the  heat,  cover  the  kettle,  and  let  it  rest  eight  or 
ten  hours.  This  time  is  necessary  to  have  a  complete  separa- 
tion. Draw  oflt*  the  lye,  which  is  strongly  colored  brown,  and 
marks  while  warm  from  22°  to  25°  B. ;  frequently,  on  cooling, 
the  lye  solidifies  into  a  gelatinous  mass.  Alone,  or  mixed 
with  new  lye,  it  is  used  in  the  pasting  of  oleic  acid. 

Second  Service  of  Lye. — This  service,  which  is  generally  the 
last,  consists  of  new  lye  at  28°  or  30°  B. 


292 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


The  lye  of  the  first  service  being  drawn  off,  pour  into  the 
kettle  about  175  gallons  of  new  1  ve  at  28°  or  30°  B.  Heat ; 
very  soon  the  mass  begins  to  boil ;  at  first  moderate  the  heat; 
but  when,  by  an  ebullition  of  five  or  six  hours,  the  paste  has 
acquired  more  consistency,  the  heat  is  increased;  then  add 
every  hour,  for  six  hours,  about  twelve  gallons  of  lye  of  coction 
at  28°  to  30°  B.  These  successive  additions  of  strong  lyes 
have  for  their  object  the  complete  saturation  of  the  soap,  and 
to  replace  the  evaporated  water. 

Towards  the  end  of  the  operation — that  is,  after  an  ebulli- 
tion of  twelve  to  fifteen  hours,  add,  as  in  the  first  service, 
from  twelve  to  fifteen  gallons  of  salt  water,  at  25°  B.  By 
this  addition,  the  paste  becomes  denser  and  harder;  its  great 
consistency  presents  obstacles  to  the  ebullition,  which  then 
becomes  tumultuous.  The  foam  w^hich  covered  the  soap  has 
entirely  disappeared  ;  the  soap  is  then  in  hard  and  dry  grains, 
of  a  brownish  color.  However,  the  end  of  the  operation  is 
indicated  by  the  following  signs : — 

1.  When  a  little  of  the  warm  soap  is  put  into  the  hand 
and  quickly  rubbed  with  the  thumb,  it  instantaneously  forms 
thin  and  hard  scales,  which  fall  from  the  hand  without  leav- 
ing on  it  any  adhering  particles. 

2.  When  the  foam  which  covered  the  surface  of  the  soap 
has  disappeared. 

3.  When,  after  fifteen  hours  of  continual  ebullition,  the 
lye  is  yet  caustic.  To  obtain  the  soap  well  grained,  it  is 
necessary  that  the  lye  extracted  from  the  kettle,  at  the  end 
of  the  operation,  should  mark  28°  to  30°  B. 

When  these  indications  are  well  defined,  the  soap  is  com- 
pletely saturated  wnth  lye.  Turn  off  the  heat,  cover  the 
kettle,  and,  after  resting  ten  hours,  draw  oft'  the  lye. 

Fitting. — For  this  operation,  the  lye  of  the  pasting  (em- 
patage)  or  a  new  lye  can  be  used.  The  first  slightly  colors 
the  soap,  but  deprives  it  more  completely  of  the  excess  of 
caustic  alkali  it  contains;  the  second  does  not  color  it,  but 
sometimes  causes  an  efilorescence  of  carbonate  of  soda ;  it  is 
then  better  to  use  the  first.    As  it  generally  marks  from  18° 


THE  FABRICATION  OF  SOAPS. 


293 


to  20°  B.,  it  is  reduced  to  8*^  or  12°  B.,  by  diluting  with 
water. 

The  Operation  is  conducted  as  follows  : — 

Two  men  stir  the  paste  continually,  while  a  third  pours  in 
the  lye  at  8°  to  12°  B.  Heat  strongly,  so  as  to  keep  the 
mixture  very  warm,  for  it  is  by  the  combined  action  of  heat, 
stirring,  and  the  successive  additions  of  weak  lyes  that  the 
grain  of  the  soap  is  broken  and  refined,  by  depriving  it  of 
the  excess  of  caustic  alkali  and  saline  substances  it  contains. 

It  is  only  w^ien  the  paste  is  sufficiently  impregnated  with 
weak  lye,  and  has  acquired  a  temperature  near  the  boiling 
point,  that  it  becomes  homogeneous  and  fluid  ;  the  soap  has 
then  the  form  of  soft,  dilated,  and  flat  grains.  Generally 
from  250  to  300  gallons  of  lye  at  8°  or  12°  B.,  are  used  in 
the  operation.  When  the  soap  is  entirely  melted  and  floats 
in  the  lye,  boil  the  mixture  gently  for  a  few  hours ;  and  to 
prevent  the  soap  from  again  becoming  granular  by  the  con- 
centration of  the  lyes,  add  from  time  to  time  a  few  pailfuls 
of  water  or  of  lye  at  2°  or  3°  B. 

In  consequence  of  the  movement  caused  by  the  ebullition, 
an  abundant  foam  appears  on  the  surface  of  the  soap ;  this 
foam  consists  of  the  most  impure  parts  of  the  paste,  and  is 
strongly  salted.  It  is  known  that  the  operation  is  finished, 
when  the  paste  which  is  under  the  foam  is  smooth,  fluid^ 
and  homogeneous ;  the  density  of  the  lye  at  the  bottom  of 
the  kettle  is  also  a  sign  to  indicate  when  the  paste  has  been 
boiled  long  enough.  When  cold  this  lye  marks  from  17° 
to  18°  B.,  at  the  end  of  the  operation.  If  below  15°,  the 
soap  would  be  less  consistent  and  less  firm;  above  19°  or  20°, 
it  would  be  too  hard.  Thus,  the  proper  degree  of  density  of 
the  lye  ought  to  be,  when  cold,  from  17°  to  18°  B. 

This  result  being  obtained,  the  heat  is  stopped  off,  and 
the  kettle  well  covered,  so  as  to  retain  the  heat  in  the  mass 
as  long  as  possible — an  essential  condition  for  a  complete 
separation  of  the  saline  matters  and  the  lye.  Indeed,  if  the 
cooling  should  be  too  rapid,  not  only  will  the  soap  not  be 
deprived  of  its  heterogeneous  and  saline  parts,  but  it  will 


29i  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


contain  a  considerable  portion  of  lye,  which  then  renders 
the  soap  less  neutral  and  less  pure. 

After  resting  forty  to  fifty  hours,  the  kettle  is  uncovered, 
and  the  scum  on  the  surface  of  the  soap  carefully  removed. 
This  scum  is  utilized  in  a  new  operation. 

The  soap  which  is  fluid,  syrupy,  and  well  melted,  is  dipped 
or  pumped  into  the  frames.  If  an  iron-wire  sieve  is  placed 
above  each  frame,  and  the  soap  passed  through  it,  the  foreign 
substances  contained  in  the  paste  will  be  separated.  The 
bottom  of  the  kettle  being  reached,  care  must  be  taken 
not  to  dip  up  any  of  the  lye  with  the  soap ;  the  latter  is 
always  easy  to  recognize  by  its  golden  color,  while  the  lye 
has  a  brown,  blackish  shade.  As  soon  as  the  lye  appears, 
manage  the  ladles  in  such  a  manner  as  only  to  remove  noth- 
ing but  the  surface  matters ;  but  whatever  be  the  care  taken 
there  is  always  a  small  quantity  of  the  lye  mixed  with  the 
soap.  To  prevent  the  inconveniences  which  would  result 
from  the  mixing  of  the  lye  with  the  refined  soap,  it  is  better 
to  pour  the  last  portions  of  soap  into  a  cylindrical  vessel, 
provided  with  a  cork  at  the  bottom.  By  resting,  the  lye 
precipitates,  and  the  soap  specifically  lighter  floats  on  the 
surface.  Then  draw  oflf  the  lye,  and  pour  the  soap  into  the 
frames. 

Paris  manufacturers  slightly  perfume  this  soap,  to  mask 
the  generic  odor  of  the  oleic  acid ;  they  generally  add  two 
ounces  of  artificial  oil  of  bitter  almonds  (oil  of  myrbane) 
for  100  pounds  of  soap. 

Stirring  the  Soap  in  the  Frames. — It  would  not  have  been 
enough  to  bring  the  soap  to  the  proper  point  of  coction  and 
purification,  if  it  could  not  be  had  perfectly  homogeneous. 
It  is  true  the  soap  would  have  the  essential  qualities  which 
constitute  a  good  oleic-acid  soap.  It  would  foam  and  be 
detersive,  but  by  the  slow  and  gradual  cooling  it  experiences 
in  the  frames,  irregular  marblings  would  be  formed.  It  might 
even  be  often  spotted  by  the  lye,  which  would  give  it  a  very 
defective  appearance. 

To  obtain  the  soap  in  a  smooth  and  homogeneous  paste, 
it  must  be  submitted  to  the  stirring  operation,  which  con- 


THE  FABRICATION  OF  SOAPS. 


295 


sists  in  agitating  the  soap  in  the  frames.  The  stirring  must 
be  continued  until  the  soap  becomes  nearly  pasty,  which  is 
easily  ascertained  by  the  difficulty  of  moving  the  stirrer. 
The  new  crutching  machine  illustrated  elsewhere  is  well 
adapted  for  this  purpose. 

The  equality  and  perfect  homogeneity  of  the  paste,  depend 
essentially  on  the  stirring  in  the  frames;  the  more  complete 
the  stirring,  the  finer  will  be  .the  soap.  This  operation  is 
performed  on  almost  all  soaps,  except  the  marbled  soap,  the 
marbling  of  which  would  be  destroyed  by  stirring.  The 
time  of  the  stirring  varies  according  to  the  nature  of  the 
pastes,  their  more  or  less  complete  liquefaction,  and  their 
temperature  at  the  time  they  are  introduced  into  the  frames. 
But,  as  a  general  rule,  soaps  composed  of  fatty  matters  in 
which  stearin  exists  in  small,  proportions,  and  the  lique- 
faction of  which  has  been  pushed  too  far,  require  a  longer 
stirring  than  those  made  of  fatty  matters  very  rich  in  stearin. 
The  stirring  of  olive  soaps  run  into  frames  of  about  2000 
pounds,  lasts  from  eight  to  twelve  hours,  according  to  the 
season;  the  stirring  may  be  discontinued  when  the  tempera- 
ture of  the  mass  is  reduced  to  43.3°  or  48.9°  C.  (110°  or 
120°  F.).  After  eight  or  ten  days  the  frames  are  opened, 
and  the  soap  divided  into  cakes. 

Thus  prepared,  this  soap  is  brownish-yellow,  but  by  being 
exposed  to  the  air,  it  becomes  white.  At  first  its  consistency 
is  somewhat  soft,  but  it  becomes  hard  in  a  short  time.  When 
well  prepared  it  is  very  detersive.  In  water  it  produces  a 
very  abundant  lather,  and  is  one  of  the  best  soaps. 

By  the  saponification  of  6750  pounds  of  oleic  acid  of  good 
quality,  the  amount  of  soap  obtained  is  10,687  pounds,  or 
155  per  cent.  The  viscous  lye  from  which  the  liquid  soap 
has  been  drawn  off,  being  mixed  with  10  per  cent,  of  salt 
water  at  25°  B.  and  boiled  for  seven  or  eight  hours,  produces 
from  four  to  five  per  cent,  of  its  weight  of  a  good  soap,  which 
only  requires  to  be  dissolved  in  a  weak  lye  to  get  rid  of  the 
excess  of  saline  substances  it  contains.  This  soap  being 
mixed  with  the  other  increases  the  amount  obtained  from 
155  to  158  or  160  per  cent. 


296 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


When  the  soap  is  to  be  moulded  it  is  divided  into  cakes, 
usually  weighing  one  pound,  and  dried  in  the  open  air  in 
summer,  and  in  a  drying-room  in  winter. 

We  give  rather  full  directions  for  this  soap,  as  it  is  a  very 
important  article  of  commerce,  utilizing  a  material  that 
otherwise  would  find  few  uses,  and  we  shall  have  occasion  to 
refer  to  it  again  in  describing  the  Swiss  soaps  and  soft  soaps. 

Of  soaps  made  by  boiling  we  have  given  those  chiefly 
known  to  commerce,  with  hints  that  any  skilful  operator 
can  apply  with  the  materials  on  hand  and  make  any  modifi- 
cation of  the  kinds  given,  calling  them  by  whatever  names  he 
may  choose.  There  are  several  boiled  soaps  known  in  Europe 
as  wax  soap  or  bleaching  soap  made  from  tallow  and  cocoa- 
nut  oil,  containing  a  larger  percentage  of  water.  Almond- 
grain  soap^  is  a  modification  of  the  mottled  soap  of  tallow, 
wherein  the  coloring  is  applied  in  a  different  manner,  causing 
white  lumps  to  appear,  called  almonds.  The  soaps  made  in 
this  country  as  imitations  of  Marseilles  soap  or  Castile  soap 
are  now  made  with  a  good  deal  of  cotton-seed  oil  in  combi- 
nation with  tallow,  etc.,  and  as  they  possess  much  interest  we 
will  here  give  the  formulas  for  Castile  soap,  either  white  or 
mottled,  made  from  cotton-seed  oil  as  a  base. 

Castile  Soap  from  Cotton-seed  Oil. 

In  our  Southern  States,  where  cotton  is  grown  in  the 
greatest  quantity  and  of  the  best  quality  in  the  world,  the 
seed  has  long  been  known  to  have  an  abundance  of  oil,  the 
extraction  of  which  was  very  difficult  on  account  of  the  ad- 
hering fibre.  From  this  cause  the  seed  was  allowed  to  rot, 
and  was  used  for  manure.  When,  however,  machinery  was 
invented  for  hulling  the  seed,  the  oil  could  be  extracted  with 
facility.  The  large  amount  of  hull  and  adhering  fibre  these 
seeds  possess  will  be  understood  when  it  is  known  that  it 
sometimes  takes  five  bushels  of  seed  to  make  one  bushel 
ready  for  the  mill.  The  hull  and  fibre  are  used  for  paper 
stock,  and  are,  of  course,  very  valuable. 

When  it  was  found  possible  to  remove  the  hull  and  make 


THE  FABRICATION  OF  SOAPS. 


297 


the  oil,  another  difficulty  arose  in  the  large  amount  of  objec- 
tionable color  the  crude  oil  contained,  and  which  was  due  to 
dark  resinous  spots  contained  in  the  seed ;  the  color,  how- 
ever, has  been  overcome,  for  it  is  now  refined  by  means  of 
chemicals,  caustic  lye,  etc.,  and  bleached  with  sulphuric  acid, 
and  pressed  to  remove  the  large  amount  of  stearine  it  con- 
tains, and  which,  with  the  oils,  is  used  for  a  great  many 
purposes,  this  latter  being  sometimes  sold  and  bottled  as 
salad  oil  from  its  sweet  nutty  taste  when  fresh  and  pure. 

Cotton-seed  oil,  when  well  refined,  is  a  bland,  bright  yel- 
lowish oil,  very  similar  to  almond  oil,  though  it  has  some  of 
the  properties  of  a  drying  oil,  but  taking  a  very  long  time 
to  dry.  This  drying  property  does  not  seem  to  deter  the 
maker  of  cheap  perfumery  from  bottling  large  quantities  for 
common  hair  oil,  or  from  buying  it  for  that  purpose  under 
the  name  of  olive  oil,  often  not  knowing  from  what  source 
it  is  obtained. 

To  the  soap-maker  it  possesses  very  valuable  properties, 
for  nothing  has  yet  been  discovered  that  is  so  good  and  eco- 
nomical a  substitute  for  olive  oil ;  and  when  a  portion  of 
lard  and  bleached  palm  oil  is  mixed  with  it,  for  making 
Marseilles  or  Castile  soap,  it  is  difficult  to  distinguish  the 
imitation  from  the  genuine  soap.  The  importance  of  this 
oil  in  the  manufacture  of  soap  is,  to  us,  so  great  that  we  deem 
it  necessary  to  devote  some  space  to  its  description,  to  give 
soap  manufacturers  some  hints  for  its  manufacture  into  a 
soap  that  may  be  called  Castile  soap,  from  its  close  resem- 
blance to  it. 

In  saponifying  cotton-seed  oil,  there  is  no  peculiar  difficulty 
more  than  in  making  a  good  Castile  soap  from  olive  oil, 
though  the  soap  is  made  somewhat  sooner  if  the  stearine  is 
left  in  it,  which  stearine  is  generally  pressed  out  to  permit 
the  oleine  to  remain  fluid  in  the  coldest  weather. 

To  make  a  white  Castile  soap,  take: — 

Cotton-seed  oil  80  pounds. 

Lard,  good  quality  10  " 

Olive  oil  10  " 


298 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


And  prepare  the  lye  by  close  calculation  in  this  manner : 
50  pounds  to  mark  15°  B.,  50  pounds  at  21°  B.,  and  50  pounds 
at  27°,  making  150  pounds  for  this  quantity  of  grease — the 
lye  to  be  made  of  the  English  caustic  soda,  and  rendered 
clear  and  caustic  with  about  one-fourth  of  lime. 

To  the  melted  grease  in  the  kettle  pour  the  first  50  pounds 
of  lye  at  15°,  keeping  it  stirred  as  the  heat  is  raised  to  boilings 
and  as  it  froths  beating  it  down  quickly  to  prevent  its  over- 
flowing; boil  for  three  or  four  hours,  when  add  by  degrees 
the  50  pounds  of  lye  at  21°,  and  boil  for  five  or  six  hours 
longer,  keeping  up  the  stirring,  and,  when  it  becomes  a  per- 
fectly smooth  mass,  turn  off  the  heat  and  let  it  rest  for  the 
lye  to  separate.  After  some  hours'  rest  the  spent  lye  is 
drawn  ofiT,  the  heat  is  raised,  and  the  last  50  pounds  of  lye 
at  27°  are  poured  in,  and  allowed  to  boil  briskly  for  four  or 
five  hours,  when  the  soap  ought  to  grain  and  appear  flakey 
when  pressed  between  the  fingers ;  when  again  turn  off  the 
heat  and  allow  the  lye  to  separate,  and  draw  off  after  some 
hours'  rest. 

In  finishing  or  fitting  a  lye  of  carbonate  of  potash  of  6°  or 
8°,  say  25  pounds  are  stirred  in  with  a  gentle  heat  until  the 
soap  presents  a  perfectly  homogeneous  syrupy  mass,  when  it 
may  be  left  to  divide — the  scum  to  the  top  and  the  gray 
soap  to  the  bottom,  with  the  fine  soap  between,  w^hich  is 
dipped  into  the  frames,  and  the  scum  and  dark  soap  kept  to 
make  the  mottled  soap. 

The  result  should  be  about  150  pounds  of  the  best  soap 
having  a  fine  white  appearance,  and  30  to  40  pounds  of  in- 
ferior soaps  that  can  be  mixed  with  the  mottled  Castile  soap. 
To  make  a 


Mottled  Castile  Soap  from  Cotton-seed  Oil. 

Cotton-seed  oil  80  pounds. 

Lard,  good  10  " 

Palm  oil,  bleached  10  " 

The  bleached  palm  oil  improves  the  odor,  causing  a  greater 
resemblance  to  Marseilles  soap,  and  is  cheaper  than  the  olive 


THE  FABRICATION  OF  SOAPS. 


299 


oil.  Sulphuretted  soda  lyes  are  preferred  by  the  French 
soap-makers  for  their  mottled  soap;  but,  as  we  are  using  the 
English  soft  lye  or  artificial  lyes,  we  will  have  to  adopt  a 
modified  process.  The  sulphuretted  crude  soda  forms  the 
colored  mottling,  the  sulphur  combines  with  the  iron  of  the 
kettle  and  other  impurities,  and  forms  the  oxide  giving  the 
blue  color,  which  turns  red  on  all  those  parts  exposed  to  the 
air. 

To  make  this  soap,  proceed  very  much  as  for  the  white 
soap.  To  the  melted  grease  pour  on  the  50  pounds  of  the 
weaker  lye  at  15°,  gently  raising  the  heat  while  they  are 
mixing,  which  should  be  done  by  gently  stirring,  and  keep- 
ing down  the  froth  by  beating,  and  regulating  the  heat  to 
prevent  too  rapid  boiling.  After  three  or  four  hours,  pour 
in  the  50  pounds  of  lye  at  21°,  and  continue  the  stirring, 
and  as  the  froth  subsides  bring  to  a  more  rapid  ebullition, 
and  when  it  granulates  shut  oiF  the  heat  and  let  it  rest  for 
four  or  five  hours.  Now  draw  off  the  sub-lye  and  pro- 
ceed to  the  coction,  by  putting  into  the  melted  soap  the 
third  50  pounds  of  lye  at  27°,  which  is  added  while  con- 
stantly beating  and  stirring.  Stir  in  also  5  pounds  of  common 
salt,  and  continue  the  boiling  for  six  or  eight  hours,  as  may 
be  required,  or  until  the  grains  separate,  as  can  be  seen  by 
taking  out  a  portion  with  a  knife  or  pressing  between  the 
fingers,  when  a  little  experience  will  show  a  flakey  scale 
free  from  the  lye  ;  let  the  heat  be  stopped  and  the  soap  allowed 
to  settle  until  next  day,  when  after  drawing  off  the  salted 
lye  it  can  be  finished.  The  soap  is  finished  with  weak  sal- 
soda  lye,  or,  if  the  soap  is  neutral,  with  water  having  a  little 
salt  in  solution,  for  if  it  needs  water  the  grains  will  appear 
hard  and  dry,  when  the  soap  will  have  to  be  boiled  until  it 
forms  a  smooth  mass.  The  soap  is  again  allowed  to  rest,  and 
the  next  day  again  thoroughly  stirred  and  put  in  the  frame, 
when  it  is  ready  for  the  mottling.  This  is  done  by  putting 
into  a  small  watering-pot  with  a  rose-spout  about  4  ounces 
of  sulphate  of  iron,  dissolved  in  a  pint  of  warm  water,  and 
pouring  it  from  the  rose  on  to  the  top  of  the  soap  in  the  frame, 
while  the  crutch  is  plunged  up  and  down  to  give  the  streaky 


300 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


marbled  appearance.  Of  course  this  requires  some  practice, 
as  it  should  present  a  uniformity  throughout  the  entire  mass, 
but  is  not  difficult  to  accomplish  with  a  little  experience. 

If  this  soap  is  carefully  made,  it  will  be  as  good  as  most  of 
the  mottled  Castile  soaps  we  import,  and  should  be  made  so 
economically  as  to  yield  a  good  profit  while  being  sold  at  a 
less  price  than  the  imported  article. 

We  have  devoted  some  space  to  the  description  of  the  man- 
ufacture of  these  soaps  from  cotton-seed  oil,  believing  that  the 
cheapness  and  other  advantages  of  the  raw  material  will 
induce  soap-makers  to  give  it  the  consideration  it  seems  to 
deserve  for  making  a  good  and  cheap  soap,  and  that  they 
may  see  a  source  of  profit  in  its  manufacture. 


THE  FABRICATION  OF  SOAPS. 


301 


SECTIO^f  XII. 

THE  FABRICATION  OF  SOAPS  (Continued). 

Extempore  and  other  Soaps. 

Extempore  soaps,  as  we  term  them,  are  called  in  France  little 
pan-soaps^  because  they  can  be  made  in  the  smallest  quantity. 
They  differ  from  the  boiled  soaps  in  containing  all  the  glyce- 
rine that  may  be  in  the  neutral  fat,  which,  as  we  have  shown, 
is  precipitated  with  the  sub-lye  in  the  process  of  separation 
with  culinary  salt,  or  by  other  means.  Thus,  soaps  are  made 
in  several  ways,  but,  by  whatever  mode  it  is  necessary  clearly 
to  calculate  the  requisite  quantity  of  alkali,  for  the  saponifi- 
cation of  a  given  quantity  of  fats,  or  the  equivalents.  When 
this  is  done,  and  the  proper  skill  is  used,  the  result  is  gener- 
ally satisfactory,  although  such  soaps  are  never  so  neutral  as 
those  made  by  boiling. 

On  the  score  of  economy  there  are  divers  opinions,  while 
much  time  is  saved,  and  the  necessary  plant  is  not  near  so 
costly,  there  is  some  additional  expense  in  the  preparation  of 
the  lye,  yet  on  the  whole,  we  would  say  that  they  cost  less  to 
make,  than  the  soaps  made  by  boiling,  particularly  at  the 
present  time,  when  the  alkalies  are  obtained  with  so  much 
facility.  These  soaps  are  now  made  largely  in  nearly  all 
commercial  countries. 

Under  this  head  may  be  classed  all  these  soaps  called  half- 
boiled  soaps,  which  we  consider  better  entitled  to  the  name 
we  propose,  Extempore  soaps,  as  they  are  made  with  rapidity 
and  retain  their  glycerine.  Thus,  when  cocoa-nut  oil  enters 
into  their  composition,  it  is  customary  to  saponify  it  sepa- 
rately in  strong  lye,  and  add  it  to  the  previously  boiled  tal- 
low, or  tallow  and  palm  oil,  or  rosin,  which  have  been  boiled 
in  a  lye  of  15°  to  21°  B.    They  are  also  marbled  in  the  frame 


302 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


by  adding  ultramarine  for  blue,  vermilion  for  red,  bole  Ar- 
menia for  brown,  bone  black  for  gray.  This,  when  skilfully 
done,  gives  an  attractive  appearance,  particularly  when  the 
soap  is  of  a  clear  white  color. 

For  all  cold  soaps,  attention  must  be  given  to  have  the  al- 
kalies as  pure  and  as  caustic  as  possible,  otherwise,  a  com- 
plete admixture  of  the  material  is  almost  impossible.  As  a 
rule,  lyes  of  38*^  B.  are  taken.  Such  a  lye  of  soda  contains 
0.3445  kilog.  (.758  lb.)  of  soda  to  each  litre  (2.1  pints) ;  so  for 
100  kilog.  (220  lbs.)  of  cocoa-nut  oil  we  require  36.8  litres  (9.7 
gals.),  and  we  obtain  about  150  kilog.  (3B0  lbs.)  soap  having 
but  25  per  cent,  of  water.  This  is  simply  an  example.  A 
larger  percentage  of  water  may  be  taken,  though  of  course 
the  lye  will  be  weaker,  but  when  cocoa-nut  oil  is  present,  it 
is  best  to  use  strong  lyes. 

As  mechanical  aid  in  making  cold  soaps  facilitates  the 
process,  there  are  made  several  styles  of  kettles  and  appa- 
ratus for  the  purpose.  We  illustrate  two :  one  being  like 
the  ordinary  soap  kettle  with  a  mechanical  stirrer ;  the 


Fig.  57.  Fig.  58. 


other  a  cylinder  placed  horizontally,  having  a  shaft  through 
the  centre  to  which  are  attached  a  number  of  arms  like  a 
churn ;  this  mode  of  usage  needs  no  further  description. 
(Figs.  57,  58.) 


THE  FABRICATION  OF  SOAPS. 


303 


Tallow  Soap  by  the  Cold  Process. 

Take,  say,  1000  kilog.  (2200  lbs.)  of  tallow,  purified  and 
cleared  by  rendering  in  a  kettle,  of  twice  its  capacity,  heated 
to  a  melting  at  about  37°  C.  to  43°  C.  (98.6°  to  109.4°  F.),  and 
the  30°  B.  lye,  being  heated  to  attain  the  same  temperature, 
is  run  from  a  vessel  provided  with  a  stopcock  into  the  kettle. 
After  having  added  all  the  lye,  the  entire  mass  is  stirred 
gently,  until  it  has  thickened  so  that  one  part  of  it,  spread 
out  to  a  ribbon,  no  longer  runs  together  with  the  other. 
The  thin  pasty  mass  is  now  run  into  the  previously  warmed 
frames,  in  which  after  a  little  while  a  tolerably  strong  heat 
takes  place,  which  denotes  the  act  of  union  between  the 
alkali  and  the  sebacic  acid.  As  long  as  the  soap  is  still  soft, 
it  shows  a  strong  alkaline  touch  ;  but  after  the  combination 
has  taken  place,  this  vanishes  almost  entirely,  provided  the 
proportions  between  the  alkali  and  the  fat  have  previously 
been  correctly  taken. 

The  soap  thus  produced  is  of  brilliant  whiteness,  very  hard 
and  brittle,  but  will  be  more  pliant,  if  about  10  per  cent,  of 
the  alkali  used  is  potash.  This  soap  lathers  very  well,  and 
is  on  occount  of  its  hardness  very  economical  for  use  ;  a  little 
addition  of  cocoa-nut  oil  makes  it  lather  still  more  freely. 

CocoA-I^'uT  Oil  Soap  by  the  Cold  Process. 

The  operation  is  performed  exactly  in  the  same  way,  as  has 
been  stated  in  the  case  of  tallow  soap,  in  which  case  it  is 
generally  perfumed  and  artificially  marbled.  The  latter  is 
done  in  this  manner.  The  soap  is  put  into  the  moulds  in 
layers,  upon  every  layer  some  vermilion  or  other  coloring, 
mixed  with  a  little  lye,  is  spread,  until  the  last  layer,  when 
it  is  stirred  in  certain  directions  with  an  iron  rod.  To  give 
the  soap  a  blue  flame-like  appearance,  ultramarine  is  used  in 
lieu  of  vermilion.  The  soap  remains  for  twenty-four  hours 
well  covered  in  the  frames,  during  which  time  the  real  com- 
bination of  alkali  with  the  sebacic  acids  with  evolution  of 
heat  occurs. 


304  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Cocoa-nut  oil  possesses  in  a  high  degree  the  property  of 
forming  soaps  which  are  capable  of  retaining  large  quantities 
of  water,  without  thereby  losing  much  of  their  hardness. 
Thus  water,  or  salted  water  may  be  added  in  the  frame,  to 
the  amount  of  50  per  cent. 

For  the  fabrication  of  all  so-called  Cold  Soaps,  the  applica- 
tion of  lyes  entirely  free  from  carbonic  acid  is  a  necessary 
condition,  if  a  good  product  is  expected,  while  only  the 
absolutely  required  quantity  of  alkali  needed  for  saponifica- 
tion is  used. 

Rosin  Soap  by  the  Cold  Process. 

The  quantity  of  rosin,  which  is  applied  to  a  given  quantity 
of  fat,  is  from  15  to  50  per  cent.  The  more  rosin  is  added 
to  a  soap,  the  more  it  attains  a  soft  and  pasty  nature,  if  the 
quantity  of  cocoa-nut  oil  or  other  fats  is  not  correspondingly 
increased.  The  number  of  rosin  soaps,  that  is  the  names 
by  which  they  are  designated,  is  according  to  the  kinds  of 
fat  used,  extraordinarily  large,  and  almost  every  large  soap 
manufactory  has  its  own  receipts,  after  which  the  favorite 
soap  is  made. 

For  the  saponification  of  the  rosin  suitably  concentrated 
lyes  are  applied,  because  they  furnish  a  firmer  soap.  Caustic 
soda  could  be  substituted  by  carbonate  of  soda,  but,  for 
reasons  already  stated,  one  cannot  well  recommend  this 
practice. 

E-osin  and  fat  are  either  saponified  separately  and  after- 
wards stirred  together,  or  the  fat  is  first  saponified  when  the 
pulverized  rosin  with  the  necessary  quantity  of  lye  is  added 
to  the  soap  and  boiled  until  all  froth  disappears.  So  also  of 
a  mixture  of  100  kilog.  (220  lbs.)  rosin,  55  kilog.  (121  lbs.) 
cocoa  oil,  and  55  kilog.  palm  oil,  a  rosin  soap  may  be  manu- 
factured in  the  cold  way.  These  substances  are  melted  to- 
gether, adding  gradually  while  constantly  stirring  100  kilog. 
(220  lbs.)  or  72  litres  (19.0  gallons)  of  a  25°  B.  soda  lye,  until 
it  becomes  stifi*,  when  it  is  put  in  the  frames.  The  frames 
are  now  covered  up  and  left  to  rest  until  the  next  day. 


THE  FABRICATION  OF  SOAPS. 


305 


Transparent  Rosin  Soap. 

For  the  fabrication  of  this  soap  Dr.  Deite  gives  the  follow- 
ing directions:  80  kilog.  (176  lbs.)  cocoa-nut  oil, and  20  kilog. 
(44  lbs.)  palm  oil  are  saponified  with  soda  lye  of  24°  B.,  ad- 
justing it  to  a  very  weak  "touch,"  and  boiled  until  the  froth 
disappears.  Then  15  kilog.  (33  lbs.)  of  pulverized  rosin  are 
thrown  into  it;  he  then  dissolves  133J  grammes  (4.67  ozs.) 
sugar  of  lead  in  100  kilog.  (220  lbs.)  salt  water  of  10°  to  20° 
B.  which  by  adding  soda  has  been  enhanced  to  20°  B.,  stirs 
this  among  the  soap,  and  then  ceases  the  boiling.  It  is  then 
run  into  the  frames  and  well  covered,  and  the  result  is  a 
semi-translucent  hard  soap. 

Another  receipt  for  making  this  soap  is  as  follows : — 

70  kilogrammes  (154  lbs.)  cocoa  oil 

80  kilogrammes  (  66  lbs.)  palm  oil 

20  to  25  kilogrammes  (44  to  55  lbs.)  rosin, 

are  saponified  over  a  slow  fire  with  a  slightly  carbonated 
caustic  soda  lye  of  86°  B.  which  adjusts  it  for  a  strong  touch. 
When  this  is  done,  the  fire  is  extinguished,  pouring  20  kilog. 
of  a  solution  of  potash  of  20°  B.  over  it,  stirring  it  well  under, 
then  adding  under  constant  stirring  70  kilog.  (154  lbs.)  solu- 
ble glass  (40°  B.),  which  has  previously  been  diluted  with  3 
kilog.  (6.6  lbs.)  alcohol  and  3  kilog.  of  a  weak  lye,  keeping 
the  soap  covered  for  a  period  of  half  an  hour,  run  it  into 
the  frames  and  cover. 

Borax  Soap,  * 

"Row  much  in  vogue,  is  generally  made  by  the  cold  process. 
The  soap  is  made  with  a  weak  "touch,"  and  there  is  a  por- 
tion of  the  alkali  left  out  and  substituted  by  a  solution  of 
borax  marking  about  12°  B.,  of  which  about  10  per  cent,  is 
used.  White  greases  are  used,  and  the  soap  has  a  brilliant 
whiteness  which  is  very  popular.  Soluble  glass  is  also  added 
to  this  soap  by  some  makers,  though  it  is  quite  likely  to 
show  in  a  white  powder  as  the  soap  dries. 
20 


306 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Swiss,  or  Half-boiled  Soaps. 

Among  the  various  names  given  to  this  class  of  soaps,  we 
prefer  this  title  as  distinguishing  them,  believing  them  to 
have  been  first  made  in  Switzerland,  where  they  are  known 
as  gluten  soaps,  a  very  unmeaning  term  and  one  calculated 
to  mislead.  They  are  soaps  that  by  their  characteristics  claim 
a  preference  with  many  people.  For  illustration  we  will  take 
for  a 

Swiss  Palm  Soap 

1000  kilogrammes  (2200  lbs.)  bleached  palm  oil, 
500  kilogrammes  (1100  lbs.)  cocoa  oil, 
1380  kilogrammes  (3036  lbs.)  25°  caustic  soda  lye, 

and  place  in  the  kettle,  and  dissolve  with  a  moderate  fire. 

1000  kilog.  palm  oil  require  for  their  saponification  110 
kilog.  (212  lbs.)  soda. 

500  kilog.  cocoa  oil  require  for  their  saponification  62.5 
kilog.  (137.5  lbs.)  of  soda;  total  =  172.5  kilog.  (379.5  lbs.) 
soda. 

A  25°  soda  lye  contains  13.90  per  cent.  soda.  We  need 
therefore  of  such  1365  kilog.  (3003  lbs.);  ac- 

cording  to  direction  1380  kilog.  (3036  lbs.)  shall  be  taken  in 
consideration  of  the  fact  that  the  areometric  degrees  may 
also  show  the  degree  of  foreign  salts,  hence  indicate  the  soda 
somewhat  too  high.  The  work  can  also  be  commenced  with 
one-half  of  the  lye,  and  the  soap  must  not  cease  to  boil.  As 
a  substitute  for  the  evaporated  water,  there  must  be  added, 
in  order  to  make  the  saponification  perfect  and  cause  the 
combination  to  take  place,  the  other  half  of  the  lye  which  is 
added  at  five  or  six  ditterent  times.  It  must  also  be  observed 
that  the  soap  does  not  fail  to  boil  continuously  for  four  or 
five  hours.  The  soap  must  have  but  a  very  weak  touch. 
Should  it  be  strong  add  oleic  acid  carefully  until  the  soap 
ceases  to  irritate  the  tongue.  That  the  soap  is  sufliciently 
boiled  is  ascertained  by  its  boiling  up  in  large  bubbles  and 
being  of  apparently  pasty  consistency,  while  the  surrounding 


THE  FABRICATION  OF  SOAPS. 


307 


portion  forms  a  honey-yellowish  bright  ring  when  a  sample 
of  it  is  cooled  and  hardened  upon  a  glass  plate,  and  when,  as 
soon  as  a  spatula  is  placed  in  the  mass  and  quickly  with- 
drawn, dry  spots  become  visible  upon  it  and  now  and  then 
knots  of  soap  adhere.  If  the  soap  has  a  fat  surplus  it  boils 
very  dull,  and  in  this  case  so  much  caustic  lye  is  added  until 
it  shows  a  weak  touch  upon  the  tongue.  Before  testing  a 
complete  cooling  off  of  the  sample  must  take  place,  since  the 
hot  soap  easily  causes  a  poignant  touch  similar  to  that  which 
caustic  lye  produces,  nor  must  the  biting  taste  of  the  cocoa- 
nut  oil  or  the  cocoa  soap  deceive  us.  The  soap  should  only 
be  considered  as  finished  when  it  ceases  to  produce  any  foam 
at  all,  and  is  of  a  honey-like  yellow,  and  telescoping  slabs  or 
rosettes  are  produced.  The  soap  now  boils  in  the  kettle  so 
that  it  can  be  heard,  since  the  steam  which  originates  upon 
the  bottom  of  the  kettle  must  break  its  way  through  the 
more  consistent  and  dense  mass  of  the  soap  and  the  burst- 
ing steam  bubbles  cause  the  loud  noise  which  is  called  the 
"talking"  of  the  soap.  When  the  soap  approaches  a  finish 
and  is  inclined  to  burn,  it  must  be  constantly  stirred.  If  the 
soap  now,  as  is  stated  above,  falls  off  the  spatula,  becomes 
dry  rapidly,  and  if  a  siunple  taken  between  the  thumb  and 
index  finger  draws  no  threads,  then  it  is  finished,  and  can, 
after  removal  of  the  fire  under  the  kettle,  be  run  into  the 
frames. 

This  of  course  is  a  soap  boiled  in  one  lye,  and  where  there 
is  no  separation  of  any  of  the  materials,  which  should  be 
well  selected  and  purified  before  beginning  the  process,  and  it 
is  particularly  applicable  to  making  toilet  soaps,  which  will 
be  more  fully  explained  under  that  head. 

So,  in  like  manner,  with  modifications  applicable  to  the 
nature  of  the  materials,  the  various  soaps  of  commerce  can 
be  made,  of  which  we  give  a  few  formulas  for  a  guide. 

Swiss  White  Wax  Soap.  Swiss  Yellow  Soap. 

Tallow  (white),  50  parts.  Tallow  oil,    30  parts. 

Cocoa-nut  oil,     20     "  Cocoa-nut  oil,  20  " 

Cotton-seed  oil,  30     "  Palm  oil,       25  " 

Rosin  (pale),  25  " 


308  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Swiss  Eosin  Soap.  Swiss  Olein  Soap. 

Palm  oil,      40  parts.  Oleine  (red  oil),  50  parts. 

Cocoa-nut  oil,  30     "  Tallow,  30  " 

Rosin,  30     "  Ground-nut  oil,  20  " 

Tliese  are  merely  hints,  and  the  manufacturer  like  any 
one  else  must cut  his  coat  according  to  his  cloth." 

A  very  fine  and  very  hard  Swiss  rosin  soap  is  obtained  as 
follows : — 

Tallow       ....      100  kilog.  (220  lbs.) 

Rosin  50  (110  ) 

Caustic  soda       ...        87^  "     (82.5  "  ) 

The  soap  is  boiled  in  two  waters  and  the  fat  substance  ia 
in  the  first  place  saponified,  with  a  13°  or  14°  B.  soda-lye, 
then  the  rosin  is  added,  and  the  boiling  continued  until  a 
soap  mass  becomes  visible ;  when  the  heat  is  turned  off,  and 
on  the  following  day  the  sub-lye  is  drawn  out.  In  the  second 
operation  it  is  boiled  with  a  10°  B.  lye,  but,  if  it  should  show; 
a  smeary  or  weak  condition,  it  can  be  remedied  with  a  lye 
of  12°  B.  The  boiling  is  now  continued  until  no  defect  is 
visible,  and  after  a  rest  of  three  hours,  the  soap  is  run  into 
the  frames. 

Another  modification  of  this  process  is,  when  the  sebacic 
acids  or  fats  are  saponified  with  the  requisite  quantity  of  caus- 
tic soda,  of  about  20°  B.,  in  a  moderate  heat  of  about  49^  C. 
(120.2°  F.),  the  ingredients  being  slowly  combined  with  con- 
stant stirring,  the  heat  gently  raised  to  a  boil,  and  sufficient 
water  added  at  times  to  keep  up  the  due  proportion  of  loss  by 
evaporation.  The  combination  is  thus  efl[*ected,  and  when  the 
paste  becomes  too  thick  to  stir  it  is  framed  and  allowed  to 
cool  slowly  for  at  least  two  days.  This  process  involves  some 
experience,  and  cannot  be  recommended  to  those  who  are 
novices  in  soap  making. 

The  main  feature  in  the  fabrication  of  these  soaps  is,  to 
keep  up  the  correct  proportion  between  alkali  and  fat.  It 
may  occur,  that  a  little  too  much  or  too  little  lye  is  applied  ; 
because,  on  a  larger  scale  the  materials  cannot  be  weighed  or 
measured  with  the  accuracy  of  an  analytical  test.    But  if 


THE  FABRICATION  OF  SOAPS. 


309 


we  have  manipulated  as  accurately  as  possible,  it  will  only 
be  an  equalizing  of  a  small  overplus  of  fat  or  lye,  and  we 
must  not  always  be  too  ready  with  ammunition  of  large  cali- 
bre, and  add  large  quantities  of  lye  and  fat  all  at  once.  This 
it  is  that  leads  to  confusion,  out  of  which  it  is  difficult  to  cor- 
rectly find  our  way  again,  and  by  which  the  soap  instead  of 
improving  is  made  worse.  All  manipulations  which  are 
undertaken  with  extempore  soaps  amount  finally  to  this,  to 
produce  the  most  neutral  soap,  and  to  fix  the  proper  propor- 
tion between  fat  and  alkali;  since  an  overplus,  be  it  of  the 
one  or  of  the  other,  works  equally  injurious. 

Hard  Soap  from  Potash  Lye. 

Prior  to  the  introduction  of  artificial  sodas,  the  lye  from 
wood  ashes  was  extensively  used  for  making  household  soaps, 
and  for  making  hard  soap  it  was  the  custom  to  boil  in  potash 
lye,  and  cut  with  culinary  salt,  either  directly,  or  in  solution. 
Where  wood  is  burnt  as  fuel,  and  wood  ashes  abound  and 
are  cheap,  or  where  potash  can  be  procured  economically, 
this  process  may  possess  interest  and  be  of  useful  applica- 
tion, although  at  present  in  commercial  centres  this  class  of 
soaps  is  rarely  made.  Yet  it  is  necessary,  for  the  reasons 
stated,  to  give  a  description  of  the  processes. 

Tallow  Curd  (grained)  Soap. 

To  transform  1000  lbs.  of  tallow  into  grained-  or  curd- 
soap,  400  lbs.  of  potash  have  to  be  taken.  The  tallow  is 
placed  in  the  kettle,  about  400  lbs.  of  lye  of  10°  B.  added, 
and  the  fire  is  kindled.  Within  a  short  time  of  the  com- 
mencement of  boiling,  the  fire  is  kept  well  up*  but  then  it 
is  moderated.  After  the  seething  up,  examination  should 
be  made  as  to  whether  the  fat  has  united  with  the  lye.  This 
is  perceived  by  the  yellow-brown  mass,  which  under  gradual 
upheaving  continues  quietly  to  boil.  What  adheres  to  the 
spatula,  when  inserted  and  withdrawn,  has  a  gelatinous,  gray- 
ish-white appearance,  without  separation  of  lye.    When  lye 


810 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


and  fat  are  not  united,  it  moves  in  the  kettle  noisily  to  and 
fro,  without  rising  upwards,  only  now  and  then  pushing  up 
in  single  places,  with  a  bouncing  noise.  The  reasons  why  fat 
and  alkali  do  not  at  first  combine,  are  in  general  the  same  as 
are  stated  in  the  section  on  soft  soaps,  and  the  remedy  is  the 
same. 

When  the  combination  succeeds  there  are  added,  at  short 
intervals,  in  four  to  five  portions,  about  1100  lbs.  of  lye  of 
16°  to  17°  B.  The  boiling  now  becomes  dense  and  languid, 
and  the  mass  appears  a  yellowish-brown,  and  runs  ofi^'  the 
spatula  in  cohesive,  long,  translucent  strings.  The  soap  boils 
to  a  paste.  If  some  of  the  soap  is  dropped  upon  a  glass, 
and  the  sample  while  yet  hot  does  not  appear  perfectly  clear, 
lye  is  yet  wanting.  A  small  portion  of  lye  should  hence  be 
added,  until  the  soap  while  hot  appears  perfectly  clear.  As 
soon  as  this  moment  arrives  the  cutting  of  the  pan  begins. 

The  salt  has  here  a  double  purpose  to  fulfil.  It  must 
transform  the  potash  soap  into  soda  soap,  and  must  separate 
it  from  glycerine,  superfluous  Avater,  lye,  and  dross.  The 
entire  portion  of  salt  necessary  for  this  purpose  is  not  added 
all  at  once,  but  a  repeated  "  salting  out"  should  be  performed. 
After  each  salting  out"  the  under  lye  is  separated  from  the 
soap,  and  the  latter  is  again  brought  into  contact  with  water 
and  salt.  Such  an  operation  is  termed  by  the  soap-boiler  a 
water^  and  he  speaks  of  a  first,  second,  and  third  water. 
By  a  boiling  of  tallow  and  potash,  when  the  materials  are 
not  very  impure,  the  "  salting  out"  is  performed  usually  in 
three  operations,  hence  the  soap  is  finished  boiling  in  three 
waters.  In  order  to  separate  the  under  lye  from  the  soap,  the 
latter  is  either  scooped  from  the  kettle  into  a  vessel  which 
stands  close  by  the  kettle,  and  afterwards  the  first  is  removed ; 
or  the  soap  remains  quietly  in  the  kettle  and  only  the  under 
lye  is  removed  therefrom.  This  may  be  done  in  two  difterent 
ways,  either  the  kettle  is  provided  below  with  a  stopcock, 
or  a  pump  with  a  movable  barrel  at  its  lower  end  is  used. 
The  salt  is  either  thrown  into  the  boiling  soap  "dry,"  or 
what  is  better,  previously  dissolved  in  boiling  water,  and 
used  as  a  solution  of  20°  B.    When  the  salt  is  used  in  the 


THE  FABRICATION  OF  SOAPS. 


311 


dry  state,  it  must  be  constantly  stirred  up  from  the  bottom 
to  prevent  its  burning. 

To  the  quantity  of  fat  taken  for  our  example,  we  apply 
in  the  beojinning  80  to  100  lbs.  of  salt.  Whether  the  applied 
salt  is  sufficient,  is  discerned  by  the  previously  brown  color 
of  the  soap  now  turning  into  white,  and  in  the  kettle  there 
appear  all  round  ebullitions  of  the  size  of  the  hand  (the  soap 
boiling  "  in  slabs"),  the  soap  beginning  to  rise  with  force,  and 
the  froth  vanishing.  Until  these  signs  appear  salt  must  be 
added.  Hereupon  the  boiling  should  continue  for  another 
hour  and  be  then  stopped,  in  order  to  cause  any  impurities 
yet  in  the  mass  to  have  time  to  settle.  The  fire  being  ex- 
tinguished, the  separation  of  soap  and  the  sub-lye  follows. 

When  the  sub-lye  is  removed  from  the  kettle,  700  to  800 
lbs.  of  w^ater  with  70  to  80  lbs.  of  salt  are  again  put  into  it, 
and  it  is  heated  to  the  boiling  point.  After  boiling  up  it 
should  be  investigated  whether  the  "cutting  of  the  pan" 
has  been  sufficiently  attended  to,  which  is  discerned  by  the 
signs  described  above.  Leaving  the  soap  to  boil  for  some 
time,  the  sub-lye  is  again  removed. 

Although  the  second  water  has  greatly  increased  the  hard- 
ness of  the  soap,  yet  this  hardness  is  not  yet  sufficient,  so 
the  third  water  must  be  prepared  to  cause  the  hardness  to 
become  perfect.  To  this  «nd  700  to  800  lbs.  of  water,  and  50 
to  60  lbs.  of  salt  are  again  heated  to  boiling,  and  again  put 
into  it.  When  it  begins  to  seethe  up  it  should  be  critically 
investigated  to  find  if  the  proper  quantities  of  salt  and  of  lye 
have  been  applied.  If  salt  is  wanting  then  froth  appears  upon 
the  surface  of  the  boiling  soap,  and  the  latter  burns  easily. 
In  this  case  salt  should  be  yet  added,  until  it  boils  up  in 
regular  slabs  of  soap.  If  too  much  salt  has  been  taken,  or 
more  correctly  speaking,  the  salt  solution  is  too  concentrated, 
the  soap  appears  upon  the  spatula  without  connection,  the 
lye  drops  rapidly  oflT,  and  little  gutters  are  formed.  This 
fault  is  remedied  by  adding  a  few  buckets  of  water.  The 
soap  must  yet  be  investigated  by  pressure.  Upon  the  thumb 
of  the  right  hand  some  soap  is  taken  and  rubbed  on  the 
palm  of  the  left  hand.     The  soap  hardens  there  almost 


312  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

instantly,  and  now  the  thumb  is  pressed  hard  upon  it  and 
rubbed.  If  the  sample  there  remains  a  cohesive  slab,  then 
the  soap  possesses  the  required  firmness,  is  solid  ;  but  if  the 
sample  crumbles,  it  needs  water;  if  smeary,  then  lye  is  want- 
ing. Then  lye  and  salt  of  15°  B.  must  be  added  till  the  proper 
state  of  the  soap  is  reached.  Thereupon  commences  the  ope- 
ration of  clear  boiling  or  fitting.  To  attain  this  the  kettle  is 
covered  one  half  with  planks,  and  a  sti  rrer  beats  down  the  mass, 
so  that  it  does  not  run  over.  The  soap  particles  dra^w  more  and 
more  together  into  globular  grains — the  soap  "grains."  The 
soap  grains  sink,  and  on  the  surface  the  kettle  is  filled  with  a 
light,  flaky  froth.  To  prevent  the  falling  of  the  mass  great 
heat  is  now  needed.  The  fire  is  diligently  kept  up,  the  entire 
kettle  is  covered  with  planks  and  cloths  spread  over  it.  The 
soap  seethes  up  with  ebullition,  and,  to  avoid  running  over, 
one  of  the  boards  is  lifted  and  the  froth  is  beaten  with  a  long 
rod  until  it  falls.  Then  the  kettle  is  again  tightly  covered, 
a  renewed  ebullition  ensues,  and  the  overflowing  is  again  pre- 
vented in  the  manner  described.  Gradually  the  violence  of 
the  ebullition  diminishes,  but  in  place  of  it  a  whistling  sound 
is  perceived  in  the  kettle.  From  time  to  time  one  of  the 
boards  is  lifted  and  the  soap  is  watched.  As  soon  as  merely 
large  perfectly  translucent  bubbles  rise  up,  the  soap  is  finished. 
After  the  fire  is  extinguished,  the  planks  are  removed,  and 
for  cooling  the  soap  a  few  buckets  of  sub-lye  are  poured 
into  the  kettle.  The  soap  is  now  ready  to  be  run  into  the 
frames,  when  care  should  be  taken  that  but  very  little  of  the 
sub-lye  is  transferred.  After  all  the  soap  is  in  the  frames 
they  are  covered  with  cloths.  From  time  to  time  the  sides 
of  the  soap  in  the  frames  are  pressed  back,  as  in  becoming 
cold  it  contracts. 

Boiling  with  wood  ashes  is  very  similar  to  that  with  potash, 
and  difters  only  in  so  far  that  the  lyes  of  ashes  are  less  con- 
centrated. In  consequence  of  this  it  is  not  possible  to 
saponify  the  fat  in  the  first  water  completely,  this  succeed- 
ing only  after  the  second  and  third  waters.  Therefore,  for 
the  second  and  third  waters  \veak  lye  is  taken,  and  not 
water,  as  in  case  of  potash.    In  order  to  saponify  453  kilog. 


THE  FABRICATION  OF  SOAPS. 


313 


(996.6  lbs.)  of  tallow,  about  50  hectolitres  (140  bushels)  of 
wood  ashes  are  to  be  put  in. 

The  boiling  with  soda  lye  presents  this  advantage,  that  the 
soap  may  be  finished  in  one  water.  The  first  lye  is  applied 
at  a  strength  of  from  10"^  to  20°  B.  The  entire  fat  is  placed 
in  the  kettle  with  one-quarter  of  the  requisite  lye  for  saponifi- 
cation, with  proper  attention  to  the  fire.  After  boiling  up,  it 
should  be  examined  as  to  whether  the  combination  has  taken 
place.  This  being  the  case,  further  portions  of  lye  are  added. 
Commonly  this  is  taken  of  a  strength  of  from  16°  to  18°  B. 
The  adding  of  lye  is  continued,  until  a  sample  of  the  soap 
upon  the  glass  plate  appears  perfectly  clear.  Thereupon  the 
"cutting  up  of  the  pan"  follows.  This  op3ration  has  here 
only  the  purpose  of  freeing  the  soap  of  glycerine  and  surplus 
water,  hence  much  less  salt  is  required  than  in  the  boiling 
with  potash  lye.  For  100  lbs.  of  fat  10  to  12  lbs.  of  salt  are 
required.  The  salt  may  be  applied  dry  or  in  solution.  After 
this  the  operations  are  the  same  as  previously  described. 

Soda  soaps  made  by  the  process  above  described  have  some 
advantages,  principally  because  it  is  impossible  to  remove  all 
the  potash,  and  they  are  generally  very  neutral  and  plastic. 


314  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


SECTIO^^  XIII. 
THE  FABRICATION  OF  SOAPS  (Continued). 

Soft  Soaps. 

Soft  soaps  are  essentially  a  combination  of  the  sebacic 
acid  soap  in  a  solution  of  potash  with  glycerine.  On  accoiint 
of  the  great  affinity  of  potash  soaps  for  water,  these  soaps 
do  not  dry  in  the  open  air,  but  always  retain  their  soft  con- 
sistency;  and  the  glycerine  dissolved  therein  to  a  certain 
degree  adds  to  this  peculiarity.  In  its  fabrication  linseed 
oil,  hemp-seed  oil,  sesame  oil,  cotton-seed  oil,  'oleic  acid  of 
the  stearic  acid  manufactories,  with  or  without  the  addition 
of  tallow  or  palm  oil,  are  used.  For  winter  soaps,  the  more 
liquid  fats  are  chiefly  used,  such  as  linseed  oil,  hemp-seed  oil, 
etc.,  since  these  do  not  congeal  so  easil}^ ;  while  in  summer 
principally  south  sea  train  oil  and  rapeseed  oil  are  applied 
in  varied  proportions. 

A  good  soft  soap  (except  the  so-called  Elaidin  soap)  must 
appear  as  a  clear  mass,  in  which  at  times,  especially  if  it  has 
been  standing  for  a  long  period,  white  grains  are  formed — 
crystalline  separations  of  stearic  acid  potash  or  soda.  It  must 
possess  the  requisite  consistency,  not  draw  into  threads  like 
rosin,  but  when  taken  between  the  finger  and  thumb  break 
off  short  like  butter  or  lard.  According  to  temperature  it 
should  be  somewhat  more  consistent  than  these  latter  articles. 
It  may  have  a  somewhat  sourish  touch  when  tasted  with  the 
tongue,  but  not  too  strong,  i.  g.,  have  a  little  overplus  of  pot- 
ash. A  large  surplus  is  denoted  by  the  dulness  of  the  soap. 
When  the  soap  is  in  want  of  alkali,  it  does  not  appear  clear, 
has,  however,  in  that  case  no  sourish  touch;  so  that  it  may 
be  easily  discerned,  whence  the  surplus  or  the  want  of  alkali 
originates. 


THE  FABRICATION  OF  SOAPS. 


815 


Until  lately,  all  soft  soaps  were  manufactured  only  by 
saponification  of  the  neutral  fats  with  caustic  potash,  and 
contained  therefore  only  the  small  portions  of  soda  that  are 
naturally  in  the  potash.  But  later,  caustic  soda  was  used 
simultaneously  in  a  fixed  proportion  to  the  potash,  partly  to 
obtain  a  somewhat  more  consistent  soft  soap,  and  partly  too, 
in  order  to  enhance  the  yield,  in  a  certain  given  quantity  of 
ingredients.  Gentele  has  given  a  certain  proportion  for  this, 
where,  without  a  muddiness  of  the  soap  occurring,  the  maxi- 
mum yield  is  reached.  For  this  purpose  5  parts  neutral 
fat  are  boiled  with  3  parts  of  potash  and  2  parts  of  soda. 
There  are  3  equivalents  of  potash  and  2  equivalents  soda,  or 
7  weight  parts  potash,  about  3  weight  parts  soda;  and  the 
soft  soap  thus  produced  consists,  therefore,  of  3  equivalents 
sebacic  acid  potash  and  2  equivalents  sebacic  acid  soda, 
besides  the  glycerine  and  water.  A  very  advantageous  re- 
sult was  obtained  by  Grentele  by  the  application  of  the  fol- 
lowing weight  proportions: — 

1420  kilogrammes  (3124  lbs.)  73  per  cent,  potash. 

970  kilogrammes  (2134  lbs.)  pure  crystallized  soda. 
8753  kilogrammes  (8256  lbs.)  liempseed  oil. 
40  kilogrammes  (88.0  lbs.)  tallow. 

102  kilogrammes  (224  lbs. )  oleic  acid. 

These  materials  yield  9720  kilog.  (21384  lbs.)  of  good  soft 
soap,  hence  almost  250  kilog.  (550  lbs.)  soap  from  100  kilog. 
(220  lbs.)  fat.  It  must,  however,  be  remarked,  that  this 
soap  contains  a  great  surplus  of  alkali ;  for  the  3895  kilog. 
(8569  lbs.)  fat  taken,  to  be  worked  up,  require  when  they 
are  saponified  with  |  potash  and  f  soda,  of  the  former 
658  kilog.  (1448  lbs.),  of  the  latter  201  kilog.  (442  lbs.), 
whereby  it  is  supposed  that  to  saponify  100  kilog.  (220  lbs.) 
fat  for  soft  soaps  19.6  kilog.  (43.12  lbs.)  potash  or  12.75  kilog. 
(28  lbs.)  soda  are  necessary.  But  since  1420  kilog.  (3124  lbs.) 
of  a  73  per  cent,  potash  correspond  with  706.5  kilog.  (1554  lbs.) 
caustic  potash,  and  970  kilog.  (2134  lbs.)  crystallized  carbonate 
of  soda  correspond  to  210.3  kilog.  (463  lbs.)  soda,  it  follows 
that  Gentele  has  applied  2486  kilog.  (5469  lbs.)  potash  and 
9.3  kilog.  (20.5  lbs.)  soda  too  much.    With  such  an  overplus 


316  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


nearly  1300  kilog.  (2860  lbs.)  more  fat  could  have  been 
saponified.  There  is  of  course  no  account  taken  as  to  loss 
ensuing  in  the  preparation  of  the  lye.  But  the  deviation 
is,  however,  too  great  not  to  suppose  at  once  an  error  in  the 
hypothesis;  perhaps  if  the  oleic  acid  were  to  be  increased 
tenfold  a  near  correspondence  of  the  common  proportions 
between  fat  and  alkali  would  take  place  in  the  soft  soaps. 
We  have  ourselves,  by  investigating  these  soaps,  repeatedly 
found  in  100  kilog.  (220  lbs.)  fat  as  much  as  21  kilog.  (46  lbs.) 
potash.  By  applying  2  equivalents  soda  to  3  equivalents 
potash,  the  soap  remains  clear,  if  otherwise  the  right  pro- 
portions are  maintained,  and  alkalies  of  a  high  degree  are 
used  in  the  making  of  lyes.  With  equal  equivalents  of  potash 
and  soda,  however,  the  soap  becomes  muddy  ;  the  same  occurs 
when  the  soda  contains  much  culinary  salt,  and  the  potash 
much  sulphate  of  potash  or  chloride  of  potassium. 

Calculating  the  proportion^  when  the  fats  are  to  be  boiled 
with  I  potash  and  §  soda.  As  we  have  already  stated,  that 
all  soft  soaps  must  be  adjusted  with  a  certain  *' touch," 
i.  e.,  with  a  surplus  of  alkali,  which  on  an  average  amounts 
to  I  more  than  if  we  had  to  do  with  the  production  of  a 
neutral  soap,  consideration  of  this  matter  should  be  taken 
from  the  first.  To  boil  100  kilog.  (220  lbs.)  into  soft  soap 
we  apply  12.8  kilog.  (28  lbs.)  soda,  or  19.5  kilog.  (43  lbs.) 
potash.  These  proportions  are  based  on  the  calculation 
made  for  saponification  of  5000  kilog.  (11,000  lbs.)  fat  for 
3000  kilog.  (6600  lbs.)  with  potash  saponified. 

^^^^100^^^  =  585  kilog.  (1287  lbs.)  caustic  potash  and 
2000  kilog.  (4400  lbs.)  with  soda  saponified  ^^^^  ^  ^^'^ 


100 

256  kilog.  (563  lbs.)  soda  will  be  required. 

The  potash  lye  applied  is  J  at  20°  to  21°  B.  and  |  at  25°  B.; 

the  first  contains  ^  ^^^^  =  438.75  kilog.  (965  lbs.)  potash, 
the  latter  =  146.25  kilog.  (322  lbs.)  potash. 


THE  FABRICATION  OF  SOAPS. 


317 


The  20°  B.  lye  contains  16.408  per  cent,  potash ;  there  are 

hence  to  be  taken  of  it  ^^^'^^ =2674  kilog.  (5883  lbs.) 

16.408 

or  1630  litres  (431  gallons.) 

The  25°  B.  lye  contains  19.803  per  cent,  potash,  and  of  it 

should  be  takeni^fA^^  =  740  kilog.  (1628  lbs.)  or  610 
19.803  ^  ^  ^ 

litres  (161  gallons). 

The  soda  is  only  applied  as  20°  lye,  and  since  it  contains 

256  X 100 

10.88  per  cent,  of  soda  there  are  required  of  it  ——^^^  = 

10.88 

2353  kilog.  (5176  lbs.)  or  2028  litres  (536  gallons).  The 
total  quantity  of  lye  contains  therefore: — 

Potash  lye  at  20O  2674  kilogrammes  or  1630  litres 
"       "    at  250  740  kilogrammes  "   610  litres 
Soda  lye   at  20o  2353  kilogrammes  "  2040  litres 

5767  kg.  (12,687  lbs.)  4280  litres  (1132  gals.) 

Whereas  from  5000  kilog.  (11,000  lbs.)  fat  (100  :  250)  12,500 
kilog.  (27,500  lbs.)  soft  soap  are  to  be  realized,  there  must  needs 
be  added  to  the  soap  mass  in  the  kettle  1737  kilog.  (3821 
lbs.)  of  water,  that  is,  the  lyes  must  be  diluted  to  the  amount 
of  7500  kilog.  (16,500  lbs.)  and  the  evaporating  water  during 
the  process  of  boiling  must  be  replaced.  Great  competition 
often  compels  the  manufacturer  to  enhance  the  yield  (100  : 
250)  by  other  means,  filling  with  salt  lye,  carbonate  of  soda, 
etc.  With  such  intention  the  fats  are  also  augmented  by 
adding  four  to  five  per  cent,  cocoa-nut  oil,  and  by  this  means 
the  yield  is  still  further  enhanced  to  300  kilog.  (660  lbs.)  soap 
from  100  kilog.  (220  lbs.)  fat. 

The  Boiling  of  Soft  Soap, — The  fabrication  of  soft  soaps 
offers  no  particular  difficulties,  if  the  proper  proportions  of 
alkali  and  fat  are  accurately  calculated  and  applied.  The 
lyes  and  all  the  fat  can  be  taken  at  once  into  the  kettle,  the 
mixture  heated  to  boiling,  and  kept  thus,  until  a  perfect 
saponification  ensues,  and  the  soap  has  attained  its  correct 
consistency.  More  to  the  purpose  it  appears,  however,  either 
all  the  lye,  or  perhaps  one-half  of  it,  is  stirred  together  with 


318  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


the  fat  in  a  temperature  of  80°  to  40°  C.  (86°  to  104°  F.)  and  to 
leave  the  mixture  stand  overnight.  By  this  operation  a  cer- 
tain emulsion  is  formed,  and  on  the  day  following,  the  further 
union  advances  extremely  fast.  If  at  first  only  one-half  of 
the  lye  had  heen  taken,  then  during  the  continuance  of  boil- 
ing, the  other  half  must  be  added.  From  time  to  time,  the 
soap  is  tested  as  to  its  nature,  whether  it  has  an  overplus  of 
fat  or  alkali,  whether  it  has  steamed  or  not.  This  is  ascer- 
tained by  placing  a  small  sample  upon  a  glass  plate,  upon 
which  it  is  cooled  off  in  a  temperature  not  exceeding  8°  C. 
(46.40°  F.).  The  soap  is  good  if  a  sample  of  it,  held  up  to  the 
light,  is  clear  and  translucent,  and  when  the  soap  dropped 
upon  the  glass,  after  a  lapse  of  from  12  to  15  minutes,  shows 
but  a  very  small  ring.  It  must  not  glide  or  be  slippery  upon 
the  glass,  and  when  taken  between  two  of  the  fingers,  it  must 
not  draw  into  threads  when  the  fingers  are  extended. 

Particular  Remarks. — Should  the  soap  at  the  commence- 
ment become  thick,  then  it  is  wanting  in  lye,  which  must 
be  added  at  once.  If  the  soap  turns  muddy  from  the  first, 
when  placed  upon  the  glass,  and  runs  like  water  from  the 
spatula,  then  the  lye  is  excessive  and  must  be  relieved  by 
adding  some  fat.  If  the  soap  runs  out  of  the  trial-spoon  in 
flakes,  it  is  too  much  evaporated,  and  must  then  be  diluted 
with  a  corresponding  quantity  of  potash  lye  of  about  4°  B., 
and  again  be  somewhat  condensed. 

The  ring  of  lye  and  the  gray  fat,  by  the  trial  upon  the 
glass,  the  first  as  a  rim  encircling  the  soap-drop,  the  latter 
as  a  muddy  point  in  the  centre  of  the  drop,  appears  only  after 
the  soap  is  so  far  boiled  that  it  is  out  of  the  paste,  hence 
almost  finished  boiling.  A  small  ring  of  lye,  every  soft 
soap  must  show,  because  every  soap  must  needs  have  a  cer- 
tain surplus  of  caustic  potash.  On  the  other  hand,  all  fatty 
gray  (a  gray  spot  in  the  centre  of  the  soap-drop)  must  be 
removed  by  adding  potash  lye. 

If  this  is  not  done,  then  the  soap  after  a  short  time  turns 
in  the  kegs  or  barrels  into  a  thick,  slimy,  and  thready  mass. 
The  barrels  into  which  the  soft  soap  is  placed  must  be  en- 
tirely clean  and  dry,  or  the  soap  will  easily  turn,  that  is, 


THE  FABRICATION  OP  SOAPS. 


319 


will  become  thin  and  muddy.  It  is  filled  while  3^et  hot  into 
the  barrels,  which  are  closed  only  after  the  soap  has  cooled 
off.  The  magazines  or  storehouses  for  the  finished  soaps  must 
not  be  too  warm. 

The  soaps  made  of  hempseed-oil  possess  a  more  or  less 
greenish  color;  all  other  fats  furnish  a  brownish  soap.  But 
since  hempseed-oil  soap  is  now  very  much  favored,  it  is 
sought  to  impart  also  to  the  soaps  made  of  other  fats  a 
greenish  hue.  This  is  done  by  dissolving  finely  powdered 
indigo  in  the  sixfold  part  of  its  weight  of  fuming  sulphuric 
acid,  and  this  solution  is  stirred  into  the  soap.  Instead  of 
this  indigo  solution,  indigo  carmine  (indigo-blue  hyposul- 
phide,  potash  or  soda)  may  be  applied.  So  much  of  this  is 
taken  until  the  desired  shade  is  attained. 

The  soft  soaps  are  likewise  filled,  and  for  this  various 
means  are  applied.  Some  add  rosin  soap  to  them.  Such  a 
mixed  soft  soap  cannot  be  used  for  washing  wool  nor  in 
fulling-mills  ;  besides  the  profit  which  the  soap  manufacturer 
thus  obtains  is  very  doubtful,  because  the  soaps  have  to  be 
boiled  more  in  order  to  attain  the  proper  consistency.  A 
frequent  mode  of  filling  is  that  with  starch  dissolved  in  weak 
lye.  By  this  operation  a  transparent,  and  almost  colorless 
gluten,  is  stirred  into  the  soap,  which  must  be  done  with 
great  care,  if  not,  little  lumps  will  form. 

Others  fill  with  alum  and  a  solution  of  salt ;  of  the  first 
1  kilog.  (2.2  lbs.)  dissolved  in  water,  and  30  to  40  kilog.  (66 
to  88  lbs.)  salt  lye  of  5°  B.  are  taken  to  700  kilog.  (1540  lbs.) 
finished  soap.  On  the  one  hand,  clay  is  separated  by  this 
operation,  which  partly  dissolves  again  in  caustic  potash  ;  on 
the  other,  some  soda  soap  is  produced.  The  filling  is  added 
after  the  soap  has  attained  its  proper  consistency.  Of  this 
soap,  worsted  spinning  manufacturers  can  make  no  use,  which 
is  to  be  well  noted. 

The  filling  with  carbonate  of  soda  in  a  lye  of  5°,  to 
w^hich,  upon  100  kilog.  (220  lbs.)  finished  soap,  2  to  4  kilog. 
(4.4  to  8.8  lbs.)  are  added.  In  this  case  it  is  the  formation 
of  a  small  quantity  of  hard  soda-soap,  which  makes  the  soap 
more  consistent,  so  that  it  need  not  be  boiled  so  lonsf. 


320  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


In  more  modern  times,  much  filling  is  also  accomplished 
by  the  use  of  soluble  glass.  This  is  carried  out  by  taking 
36  kilog.  (79  lbs.)  soluble  glass,  for  100  kilog.  (220  lbs.)  oleic 
acid  or  fat.  Inasmuch  as  the  soluble  glass  contains  an  over- 
plus of  silicic  acid,  it  becomes  necessary  to  admix  to  each  25 
kilog.  (55  lbs.)  soluble  glass,  1  kilog.  potash  lye  of  25°  B., 
since  the  soap  may  otherwise  become  too  weak.  The  mixing 
of  the  soap  with  the  soluble  glass  is  performed  by  stirring  in 
well,  without  heat. 

Grained  Soft  Soap.  {Fig  Soap.) — By  this  appellation  such 
soaps  are  known  whose  brown,  trans|)arent  mass  is  more  or 
less  filled  with  smallish  white  grains,  crystals  of  stearic  acid, 
or  palmitic  acid,  potash  or  soda.  The  formation  of  these 
soaps  succeeds  best  in  a  temperature  of  between  9°  and  18°  C. 
(48.2°  to  64.4°  F.).  Below^  9°  C.  (48.2°  F.)  the  mass  congeals 
too  ra[)idly,  so  that  no  crystalline  separation  will  ensue; 
above  14°  C.  (57.2°  F.)  the  crystals  all  remain  dissolved. 
To  produce  this  soap,  the  purest  potash-lye  must  be  applied. 
The  potash  from  which  this  lye  is  prepared  must  not  exceed 
5  per  cent,  of  carbonate  of  soda,  and  must  also  be  free  from 
other  foreign  salts.  Otherwise,  the  entire  mass  becomes 
muddy,  and  the  grains  can  no  longer  be  discovered  therein. 

There  are  various  directions  for  producing  this  soap,  of 
which  a  few  are  here  given  : — 

I.  55  parts  palm  oil  and  45  parts  oleic  acid,  or 
II.  55     "      "       "      15  parts  tallow  and  30  parts  linseed  oil,  or 
III.  70     "       *'  30  parts  linseed  oiL 

These  soaps  are  also  adjusted  upon  a  certain  "touch";  just 
as  the  applied  fats  are  more  or  less  hard,  the  crystallizations 
are  also  more  or  less  numerous,  so  that  by  the  choice  of  the 
fats  it  is  in  our  power  to  produce  more  or  less  crystals  in 
the  soap.  Perutz  communicates  the  following  directions  for 
the  fabrication  of  an  excellent  fine  soda-grain  soap,  which 
upon  its  clear  green  ground  has  but  a  few  white  grains.  This 
soap  is  made  of  f  oil  of  hemp-seed,  and  J  tallow. 

Artificial  Grain  Soap. — The  above  explained  grain  soft  soap 
is  also  as  to  its  exterior  appearance,  produced  in  an  artificial 
manner,  by  admixing  with  the  finished  soap  certain  grainy 


THE  FABRICATION  OF  SOAPS. 


821 


substances.  The  so-called  "artificial  grain"  consists  usually 
of  starch,  lime,  or  clay,  which  is  made  into  the  shape  of  grains. 
The  most  suitable  is  clay,  if  we  at  all  desire  to  assist  in  lend- 
ing a  helping  hand  to  such  a  deception. 

Elaidin  Soft  Soaps. — These  soaps  contain,  in  comparison  to 
potash,  a  larger  proportion  of  soda  than  the  common  soft 
soaps,  in  consequence  of  which  they  become  muddy  when 
cooled  off,  and  wlien  stirred  again,  assume  a  silvery  or 
golden  shiny  appearance.  According  to  the  nature  of  the 
fat,  they  show  a  yellow  or  yellowish  white  color;  for  their 
production,  more  hard  fats  are  used  than  others.  The  first 
half  of  the  fat  boiled  in  potash,  the  other  in  soda,  furnishes 
a  good  and  smooth  soft  soap. 

IN'umerous  are  the  receipts  for  the  fabrication  of  elaidin 
soaps,  which  differ  partly  on  account  of  the  various  fats, 
partly  on  account  of  the  proportions  of  the  various  mixed 
fats  which  are  to  be  saponified.  The  manipulation  is  the 
same  as  in  the  case  of  the  common  soft  soaps.  They  are 
adjusted  until  a  sample,  placed  upon  the  glass  plate,  shows 
a  small  lye  ring  when  cooled  off.  The  disappearance  of  the 
froth  in  clear  boiling  here  also  designates  the  approaching 
end  of  the  boiling.  And  this  offers  a  tolerably  sure  sign 
that  all  the  alkali  has  combined  with  the  sebacic  acids.  For 
our  ownselves,  we  have  no  doubt  that  the  carbonate  of 
alkalies,  when  tlie  saponification  does  once  take  place,  will 
to  a  certain  degree  decompose  the  neutral  fats  and  change 
them  into  soap.  At  first  the  caustic  alkali  is  absorbed 
while  boiling,  further  also  the  carbonate  of  alkali  is  changed 
as  long  as  fat  is  still  on  hand.  This  transformation  ensues 
under  the  development  of  carbonic  acid,  which  is  really 
the  cause  of  the  frothing.  The  ceasing  of  frothing,  or, 
what  is  the  same,  of  carbonic  acid  development,  is  therefore 
a  sure  sign  that  a  reciprocal  influence  of  the  materials  no 
longer  takes  place.  Inasmuch  now  as  the  lyes  which  find 
application  in  the  manufacture  of  soap — as  may  be  boldly 
asserted — are  never  perfectly  caustic,  we  would,  when  the 
carbonate  of  alkalies  in  the  presence  of  caustic  alkali  and 
finished  soap  were  not  decomposed  in  all  cases  from  the  be- 
21 


822 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


ginning,  have  to  employ  a  so  much  larger  overplus  of  alkali, 
as  the  lyes  contained  carbonate  of  alkali.  A  certain  limit, 
however,  it  seems  must,  in  this  case,  not  be  transgressed,  if 
we  do  not  desire  to  run  the  risk  of  continuing  the  boiling 
very  long,  or  until  a  perfect  saponification  ensues,  and  cause 
a  loss  of  time  and  fuel. 

The  following  receipts  are  effective  for  making  good  elaidin 
soaps : — 

600  kilog.  (1320  lbs.)  palm  oil  (bleached), 
300  "  (660  lbs.)  linseed  oil, 
saponified  part  with  potash, part  with  soda,  with  say  3  parts 
potash  and  2  parts  soda.  These  are  about  the  proper  equiva- 
lents. Another  formula  is,  45  parts  palm  oil,  55  parts  oleic 
acid;  40  parts  palm  oil,  30  parts  oleic  acid,  and  30  parts 
linseed  oil.  The  more  the  quantity  of  the  soda  is  increased 
in  proportion  to  the  potash,  the  greater  the  consistency, 
the  harder,  but  also  the  less  clear  the  elaidin  soaps  appear. 
But  in  this  respect  we  must  govern  ourselves  according  to 
the  desires  and  the  customs  of  the  consumers.  Many  give 
to  the  elaidin  soaps  an  addition  of  rosin  ;  but  in  most  cases 
there  ensues  from  this  no  profit,  either  for  the  consumer  or 
for  the  manufacturer. 

White  Soft  Soaps. — By  this  name  a  soap  is  known  in  many 
places,  which  really  cannot  be  counted  among  the  soft  soaps, 
since  as  to  its  main  substance  it  is  composed  of  a  soda  soap, 
filled  with  chloride  of  potassium.  It  is  produced  by  saponi- 
fying 75  parts  tallow  and  25  parts  cocoa  oil  with  2  parts 
caustic  potash  and  1  part  caustic  soda  lye.  The  previously 
mixed  lyes  are  added  by  degrees  until  the  soap  attains  a 
strong  ''touch."  Thereupon  so  much  salt  lye  of  20^  B.  is 
stirred  in,  until  a  sample,  when  cooled  off,  forms  a  stiff 
paste,  which  by  a  pressure  of  the  fingers,  extends  upon  the 
glass  plate.  The  soap  is  now  finished  and  is  to  be  filled  into 
the  barrels,  where,  after  it  becomes  cold,  it  will  be  found  to 
be  so  firm  that  it  cannot — like  other  soft  soaps — be  taken  out 
with  the  spatula,  but  must  be  cut  out  with  a  knife.  100  parts 
of  the  fats  furnish  400  parts  of  a  cheap,  but  very  inferior  soap. 


THE  FABRICATION  OF  SOAPS. 


323 


A  very  pure  soft  soap,  much  esteemed  by  manufacturers,  is 
the  English  Crown  Soap  (first  quality).  In  England,  the  lyes 
are  made  perfectly  caustic,  and  of  two  strengths,  the  weakest 
being  8°  B.,  and  the  strongest  25°  to  30°  B.  For  eighteen  bar- 
rels, prepare  400  gallons  of  lye,  with  good  potash  made  caustic 
with  lime;  and  put  a  third  of  it  in  the  kettle,  and  then  add 
52  pounds  of  suet,  and  as  much  of  lard.  When  the  whole  is 
melted,  pour  in  70  gallons  of  olive  oil,  and  leave  the  liquor 
to  settle  for  two  hours ;  kindle  the  fire  anew,  and  turn  19 
gallons  of  lye  into  the  kettle.  As  soon  as  ebullition  com- 
mences, add  from  time  to  time  a  little  lye  in  order  to  allay 
the  frothing.  Continue  this  addition  until  the  liquor  in  the 
kettle  has  been  reduced  one-half.  At  this  time  examine 
whether  the  soap  has  been  dosed  too  little  or  too  much  with 
lye.  This  test,  or  proof,  should  be  made  frequently  during 
the  saponification.  It  is  merely  to  withdraw  a  sample  from 
the  kettle  upon  a  spatula  and  to  examine  it.  If  it  becomes 
whitish,  and  falls  in  short  pieces,  it  is  too  alkaline,  and  re- 
quires oil ;  if,  on  the  contrary,  lye  is  needed,  it  drops  in  long, 
ropy  strings.  If  it  is  proper,  that  is,  deficient  neither  in  lye 
nor  in  oil,  the  sample  should  be  viscid,  white,  and  semi- 
transparent.  Then  the  fire  must  be  extinguished,  and  the 
soap  run  off  into  barrels.  It  may  be  as  well  to  say  that,  after 
the  second  time  the  fire  is  kindled,  the  soap  should  be  kept 
in  lively  ebullition,  until  its  preparation  is  well  advanced  ; 
and,  at  that  point,  it  must  be  carefully  managed  until  the 
soap  has  acquired  its  requisite  clarification. 

Croion  Soap  (second  quality). — For  this  soap,  take  286 
pounds  of  suet  or  tallow;  lye,  135  gallons;  sperm  oil,  80 
gallons.  Place  in  the  kettle,  first,  94  gallons  of  lye  and  the 
tallow,  and  when  the  latter  is  melted,  add  the  oil,  and  put 
out  the  fire.  Two  hours  after  kindle  it  anew,  add  19  gallons 
of  lye,  and  carry  the  whole  to  boiling,  and  keep  it  so  until 
the  soap  becomes  half  made.  Then  dose  with  9  gallons  of 
lye,  and  finally  resume  and  continue  the  ebullition,  taking 
care  to  add  the  remaining  9  gallons  of  lye  to  finish  the  soap. 

Green  Soft  Soap. — Two  hundred  and  seventy-three  gallons 
of  whale  or  cod-liver  oil,  and  400  pounds  of  tallow  are  put 


324  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


into  the  soap  pan  with  250  gallons  of  potash  lye,  containing 
250  pounds  of  dry  caustic  potash.  Heat  heing  applied  to  the 
pan,  the  mixture  froths  up  very  much  as  it  approaches  the 
boiling  temperature,  but  is  prevented  from  boiling  over  by 
being  beaten  down  on  the  surface.  Should  it  soon  subside 
into  a  doughy-looking  paste,  it  is  to  be  inferred  that  the  lye 
has  been  too  strong.  Its  proper  appearance  is  that  of  a  thin 
glue.  There  should  now  be  introduced  about  42  gallons  of  a 
stronger  lye,  containing  55  pounds  of  potash,  and  after  a 
short  interval  an  additional  42  gallons;  and  thus  successively 
till  nearly  600  such  gallons  have  been  added  in  the  whole. 
After  sufficient  boiling  to  saponify  the  fats,  the  proper  quality 
of  soap  will  be  obtained,  amounting  in  quantity  to  6400 
pounds,  from  the  above  quantities  of  materials. 


THE  FABRICATION  OF  SOAPS. 


325 


SECTIOIS'  XIV. 

THE  FABRICATION  OF  SOAPS  (Concluded). 
SiLICATED  AND  OTHER  FiLLED  SOAPS. 

The  filling  and  the  sophistication  of  soaps  is  conducted  to 
a  greater  or  less  extent  in  all  business  centres,  and  when  the 
materials  used  are  harmless  and  do  not  detract  from  the  de- 
tei'sive  power  of  the  soap,  they  may  be  somewhat  excused 
from  that  censure  which  all  adulterations  should  receive. 
The  materials  generally  used  are  water,  soluble  glass,  dex- 
trine, starch,  clay,  silica,  sand,  salt,  etc.,  and  there  are  many 
common  soaps  made  from  offal  fat,  bones,  etc,  in  which  are 
retained  the  many  impurities  natural  to  these  substances. 

In  regard  to  water  it  may  be  stated  that  the  soaps  made 
from  cocoa-nut  oil  have  the  property  of  absorbing  large 
quantities  of  water,  without  essentially  losing  thereby  their 
hardness.  This  property  the  cocoa-nut  oil  transfers  also  to 
the  soaps  in  which,  in  combination  with  other  fats,  it  ap- 
pears. The  common  soaps  contain  35  to  50  per  cent,  of 
water,  but  there  are  some  cocoa-nut  oil  soaps  in  the  mar- 
ket, which  contain  as  much  as  75  per  cent,  of  water.  Such 
soaps  shrink  greatly  in  drying,  and  are  covered — when  they 
contain  an  overplus  of  alkali — w^ith  a  crust  of  fine  white 
crystals.  Since  the  cocoa-nut  oil  soaps  are  not  separated  even 
by  greatly  concentrated  solutions  of  culinary  salt,  they  may  be 
impregnated  with  a  large  amount  of  salt  water,  without  injur- 
ing their  exterior  appearance  in  the  least.  This  may  also  be 
done  to  a  less  extent  with  soaps  which  are  fabricated  with 
cocoa-nut  oil  and  other  fats.  In  relation  to  this,  the  action  of 
the  different  soaps  is  this:  pure  cocoa-nut  oil  soaps  bear  a 
great  deal  of  salt ;  those  of  palm  oil  very  little,  and  those  of 
olive  oil  and  tallow  no  salt  at  all. 


326 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


For  filling  these  soaps  there  are  applied,  besides  water  and 
culinary  salt,  starch,  offals  (bones  and  greaves),  chalk,  clay, 
barytes,  pumice  stone,  sand,  soluble  glass,  and  carbonate  of 
soda.  Of  these  substances,  chalk  is  beyond  dispute  the  very 
worst,  because  it  does  not  merely  make  the  soap  thin,  but  in 
a  great  measure  entirely  destroys  it,  and  causes  it  to  be  ineffi- 
cient. 

Common  Cocoa-nut  Oil  Soaps. — 1000  kilog.  (2200  lbs.)  cocoa- 
nut  oil  are  boiled  with  1660  kilog.  (3652  lbs)  of  a  7.5  per 
cent,  caustic  soda  lye  into  a  clear  paste  and  filled  with 
1000  kilog.  of  a  salt  solution  of  22°  B.  The  frames  must 
be  well  greased,  because  the  soap  is  very  thin,  and  scarcely 
combines.  It  may  be  marbled  in  the  frames,  with  some  ver- 
milion or  ultramarine,  and  perfumed  with  essential  oils. 

Common  Filled  Rosin  Soaps : — 

1000  kilog.  crude  palm  oil.  110  kilog.  (242    lbs.)  caustic  soda. 

1000    "     cocoa-nut  112.5  "     (247.5  "  )     "  " 

1000     "     rosin.  104.0"     (228.8  "  )     "  " 

The  soda  is  applied  as  a  lye  of  20°  B.  =  10.677  per  cent., 

and  hence  uses  ^'^'^  ^        =  3060  kilog.  (6732  lbs.)  =  2240 
10.677  ^  ^  ^ 

litres  (593  gals.),  which,  added  in  three  portions,  is  boiled 
until  the  potash  shows  but  a  slight touch."  The  boiling 
is  continued  until  the  paste  becomes  thick,  and  after  cooling 
off  upon  the  spatula  becomes  firm.  When  in  the  frames,  50 
to  75  kilog.  (110  to  165  lbs.)  of  a  solution  of  sulphate  of  pot- 
ash of  20°  B.  may  be  stirred  in,  which  must  be  continued 
until  the  soap  becomes  tolerably  cool,  stiff  and  thick.  The 
frames  should  not  hold  more  than  200  to  250  kilog.  (440  to 
550  lbs.)  of  soap,  and  not  exceed  60  centimetres  (23.62  inches) 
in  height.  They  can  be  also  filled  with  clay,  using  for  each 
frame  15  to  20  kilog.  (33  to  44  lbs.).  The  stirring  must  be  con- 
tinued until  the  crutch  draws  furrows,  and  upon  the  surface 
partly  dry  spots  make  tbeir  appearance.  Sometimes  a  solu- 
tion of  potash  is  stirred  into  the  frames,  i.  e.,  to  200  kilog. 
(MO  lbs.)  add  15  to  20  kilog.  solution  of  20°  B.,  which 
makes  the  same  very  plastic. 


THE  FABRICATION  OF  SOAPS. 


327 


Soluble  Glass  Soap  {Silicated  Soap). — The  manufacture  of 
soluble  glass  soap  became  a  real  necessity  when,  some  years 
ago,  rosin  became  so  expensive  on  account  of  the  war,  that  it 
could  no  longer  be  used  for  making  soaps,  and  manufacturers 
were  compelled  to  substitute  other  ingredients. 

The  directions  for  making  this  soap  vary,  principally  as  to 
the  quantity  of  soluble  glass  which  is  to  be  incorporated  into 
a  soap,  and  which  is  from  25  to  60  per  cent.  The  method  of 
manufacture  consists  in  adding  to  the  hot  soap  paste  the 
desired  quantity  of  soluble  glass,  which  must  be  thoroughly 
stirred  under,  up  to  the  moment  of  congealing.  The  soluble 
glass  must  also  be  saturated  as  much  as  possible  with  silicic 
acid,  because  a  salt  wliich  is  poor  in  silicic  acid  combines  but 
in  small  proportions  witli  tlie  soap.  This  soluble  glass  soap, 
when  made  with  unbleached  palm  oil,  attains  a  yellowish 
color.  It  often  contains  60  per  cent,  of  soluble  glass,  and 
has  a  tolerable  consistency,  is  not  stickj^  like  rosin  soap,  is 
free  from  the  disagreeable  smell  of  the  latter,  and  foams  like 
common  soaps.  It  is  deserving  of  especial  mention  that 
these  soaps  are  frequently  sold  for  rosin  soaps,  although  they 
contain  no  trace  of  rosin.  The  crutching  machines  illustrated 
elsewhere  are  used  for  the  mechanical  admixture  of  the  soluble 
glass  and  other  tilling. 

Silicated  soaps  are  also  a  numerous  class  of  soaps  now  found 
in  all  markets  under  a  great  variety  of  names,  as  sand,  crys- 
tal, diamond,  etc.  They  are  simply  a  common  soap  usually 
containing  rosin,  as  that  appears,  by  its  tenacious  consistency, 
to  have  the  power  to  best  hold  their  heavy  materials.  We 
give  several  processes. 

Gossage's  Process. — This  method  consists  in  the  mechanical 
mixture  of  soluble  glass  with  the  soap  paste.  The  soluble 
glass  is  a  thick,  viscid  liquor,  made  by  fusing  together,  in  a 
reverberatory  furnace,  9  parts  of  50  per  cent,  soda  ash,  with 
eleven  parts  of  clean  sand,  or  powdered  quartz,  for  hard 
soaps ;  or  equal  weights  of  dry  pearlash  and  sand,  for  soft 
soaps.  When  the  mixture  has  combined,  it  is  drawn  off  into 
moulds,  quenched  with  water,  ground  in  the  eccentric  mill, 
and  boiled  with  alkaline  water.    The  solution,  when  com- 


328 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


plete,  is  next  evaporated  until  it  reaches  49°  B.  It  is  then 
ready  to  be  mixed  with  the  soap  paste  in  the  pan,  and  just 
as  it  has  reached  the  condition  in  which  it  is  generally  trans- 
ferred into  the  frames.  The  temperature  of  both  glass  and 
soap  paste  should  be  about  71.1°  C.  (160°  F.)  at  the  moment 
of  mixing,  which  must  be  thorough,  to  promote  perfect 
homogeneity  of  the  soap  paste.  This  is  accomplished  by 
machinery  described  below,  or  with  the  crutching  machine. 
When  the  mixture  has  cooled  to  65.5°  C.  (150°  F.)  it  is  put 
into  the  frames  and  again  stirred  with  the  crutch  until  it 
begins  to  stiffen. 

Rosin  soap  which  is  to  be  treated  by  this  process  may 
contain  rosin  in  as  large  proportions  as  one  to  two  of  fatty 
matters.    The  solution  of  glass  must,  for  this  soap,  mark  51° 

B,  ,  and  be  added  to  the  paste  when  it  is  "fitted"  and  ready 
to  be  "framed." 

The  apparatus  referred  to  consists  of  a  circular  tub  or  ves- 
sel (Fig.  59),  marked  A  in  the  drawings  hereunto  annexed, 
having  the  shape  of  an  inverted  cone,  and  an  internal  diameter 
of  about  two  feet  two  inches  at  its  lower  part,  and  three  feet 
six  inches  at  its  upper  part,  and  a  depth  of  about  six  feet. 
Adapted  to  this  vessel  is  a  central  upright  shaft,  marked  B 
in  the  drawings  hereunto  annexed,  supported  by  a  foot-step 

C,  fixed  to  the  bottom  of  the  tub  or  vessel,  and  by  a  journal 

D,  adapted  to  a  metallic  bridge-piece  E,  which  is  fixed  over 
the  tub  or  vessel,  and  secured  by  screws-bolts  to  the  sides 
thereof.  A  bevelled  cog-wheel  to  the  upper  part  of  the  said 
upright  shaft,  and  a  horizontal  shaft,  supported  by  suitable 
bearings  attached  to  the  said  tub  or  vessel,  and  on  such 
horizontal  shaft  another  bevelled  cog-wheel  in  such  manner 
that  its  cogs  will  work  in  gear  with  the  cogs  of  the  bevelled 
wheel  on  the  said  upright  shaft.  A  driving  pulley  on  the 
said  horizontal  shaft,  runs  by  means  of  a  band  passing  around 
such  driving  pulley,  also  around  another  driving  pulley, which 
is  caused  to  revolve  by  some  mechanical  power,  which  com- 
municates a  revolving  motion  to  the  driving  pulley  on  the 
said  horizontal  shaft,  and  through  this  to  the  bevelled  w^heels 
and  upright  shaft.    The  speeds  and  diameters  of  the  pulleys 


•  THE  FABRICATION  OF  SOAPS. 


329 


and  wheels  emploj-ed,  are  so  that  the  said  upright  shaft  may 
be  caused  to  make  from  sixty  to  eighty  revolutions  per  min- 
ute. Fixed  on  the  said  upright  shaft  is  a  closed  tub  or  vessel 
(marked  F,  in  Fig.  59,  1),  which  said  tub  or  vessel  is  of  such 
diameter  as  to  admit  of  its  being  placed  in  the  larger  but 
or  vessel  A,  and  to  leave  a  space  of  about  two  inches  be- 
tween the  said  two  vessels  at  their  lower  part,  and  a  space  of 
about  six  inches  at  their  upper  part.  Attached  to  the  out- 
side of  such  inner  tub  or  vessel  (by  means  of  screws  or  other- 
wise) are  a  number  of  projecting  blades  marked  I  I,  made 
by  preference  of  sheet-iron,  of  such  length  as  to  approach 
within  about  half  an  inch  of  the  inside  of  the  larger  tub  or 
vessel  A.  G  is  a  spout,  having  a  movable  stopper  H,  to  the 
lower  part  of  the  vessel  A,  through  which  to  run  off  the 


Fig.  59. 

1.  2. 


contents  of  the  vessel.  In  place  of  fixing  a  smaller  tub  or 
vessel  on  the  upright  shaft  B,  on  which  to  attach  projecting 
blades,  can  be  attached  projecting  blades  to  the  said  shaft  as 
shown  in  Fig.  59,  2.  When  this  arrangement  is  adopted, 
other  projecting  blades,  marked  K  K,  are  attached  to  the 
inside  of  the  vessel  A,  which  projecting  blades,  K  K,  are  so 
placed  as  to  admit  of  the  blades  I  I  revolving  between  them, 


330 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


as  shown  in  Fig.  59,  2.  When  about  to  use  this  apparatus 
for  the  production  of  compound  soap  by  mixing  genuine 
soap  with  viscous  solution  of  soluble  glass,  it  is  well  to 
ascertain  previously  the  highest  temperature  at  which  the 
mixture  of  such  genuine  soap,  with  the  proportion  of  the  vis- 
cous solution  employed,  will  become  too  thick  to  admit  of  its 
flowing  from  such  mixing  apparatus.  It  is  then  preferable  to 
make  a  preparatory  mixing,  by  means  of  paddles  or  crutches, 
of  the  genuine  soap  with  the  viscous  solution  employed,  in 
such  a  tub  or  vessel  as  will  contain  about  half  a  ton  of  soap, 
adding  the  soap  and  viscous  solution  at  such  temperatures 
as  will  yield  a  mixture,  having  a  mean  temperature  about 
ten  degrees  higher  than  the  previously  ascertained  tempera- 
ture hereinbefore  referred  to.  Then  transfer  the  soap,  which 
has  undergone  a  preparatory  mixing,  into  this  apparatus, 
and  cause  rapid  revolving  motion  to  be  given  to  its  vertical 
shaft,  which  communicates  corresponding  motion  to  its  pro- 
jecting arms  or  blades.  Then  withdraw  the  sliding  stopper 
of  the  said  spout  to  such  extent  as  to  allow  the  compound 
soap,  in  the  state  of  perfect  mixture,  to  flow  from  the  mix- 
ing apparatus,  and  then  put  further  quantities  of  genuine 
soap  and  viscous  solution  of  soluble  glass,  which  have  under- 
gone a  preparatory  mixing,  as  hereinbefore  described,  into 
the  said  mixing  apparatus.  The  mixed  compound  soap  pro- 
duced is  conveyed  to  the  ordinary  'frames'  in  which  it  be- 
comes solid  by  cooling.  In  mixing  viscous  solution  of  soluble 
glass  with  genuine  soap  (whether  such  mixing  may  be  sub- 
sequently completed  by  '  crutching'  in  frames  or  by  means  of 
the  improved  mixing  apparatus),  it  is  best  to  commence  such 
mixing  by  adding  a  portion  of  such  solution  at  a  specific 
gravity  of  about  1.300,  and  to  add  the  remaining  portions 
required  for  the  mixing  at  increasing  specific  gravities, 
so  that  the  average  specific  gravit}^  of  the  whole  solu- 
tion used  may  be  equal  to  that  which  has  been  found  (by 
previous  trials)  to  be  suitable  to  yield  a  compound  soap  of 
proper  hardness  when  using  a  genuine  soap  of  the  composi- 
tion employed.  When  it  is  desired  to  })roduce  a  compound 
soap,  having  less  detergent  power  than  the  compound  soaps 


THE  FABRICATION  OF  SOAPS. 


331 


obtained  by  mixing  genuine  soaps  of  ordinary  qualit}^  with 
solution  of  soluble  glass,  let  a  portion  of  the  alkali  con- 
tained in  such  solution  be  combined  with  rosin  or  with  fatty 
or  oily  acids  obtained  from  tallow  or  oil  by  well-known  pro- 
cesses. Such  combinations  are  effected  by  boiling  rosin  or 
fatty  or  oily  acids  with  solution  of  soluble  glass,  in  the  same 
manner  as  rosin  and  other  soap-making  materials  are  com- 
bined with  alkali  in  the  ordinary  process  of  soap-making, 
and  we  use  the  product  thus  obtained  to  mix  with  genuine 
soap,  and  thus  produce  less  detergent  compound  soap  con- 
taining solution  of  soluble  glass. 

Dunn's  Silicic  Soap. — In  this  process,  the  silicic  matter  is 
made  to  combine  with  the  soap  under  pressure.  Mr.  Dunn, 
the  author,  says  that  it  is  as  applicable  to  all  other  kinds  of 
soap,  even  where  silica  is  not  an  ingredient;  and  with  the 
advantage  over  the  usual  mode  of  boiling  soap  materials,  of 
effecting  a  more  perfect  union  of  the  ingredients,  in  a  shorter 
time,  with  less  waste,  and  at  a  diminution  of  expense. 


Fig.  60. 


Take  the  materials  for  soap  in  the  usual  proportions,  say 
for  yellow  soap,  7  cwt.  of  tallow,  3  cwt.  palm  oil,  8  cvvt.  of 
rosin,  and  140  to  150  gallons  caustic  soda  lyes,  21°  B.,  and 
place  the  whole  in  a  steam  boiler,  such  as  is  represented  by 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Fig.  60.  The  boiler  should  be  furnished  with  a  man-hole, 
safety  valve,  and  all  the  ordinary  appendages  of  such  an 
apparatus,  with  a  thermometer  plunged  into  a  mercury 
chamber.  There  should  be  a  feed  pipe  as  at  A,  and  a  dis- 
charge pipe  as  at  C,  through  which  the  soap  may  be  dis- 
charged into  a  pan  or  frame  as  at  D.  The  fire  being  kindled, 
the  pressure  on  the  valve  should  be  such  as  to  allow  the 
temperature  in  the  boiler  to  rise  gradually  to  about  154.4°  C. 
(310°  F.).  When  it  has  remained  at  this  height  for  about 
an  hour,  the  ingredients  may  be  discharged  from  the  boiler 
into  the  pan  or  frame,  and  allowed  to  cool  down,  when  the 
process  of  saponification  will  be  found  to  have  taken  place. 

When  silica  is  to  be  added,  it  must  be  put  through  a  pre- 
paratory process,  which  is  as  follows:  Crushed  flint  or  quartz 
mixed  with  caustic  soda  or  potash  lye,  in  the  proportion  of 
one  cwt.  of  silica  to  100  gallons  of  lye  of  21°  B.,  is  placed  in 
a  steam-tight  boiler,  or  apparatus,  such  as  above  described, 
and  the  whole  heated  to  a  temperature  of  about  154.4°  C. 
(310°  F.),  and  kept  at  this  pressure  for  about  three  or  four 
hours,  when  it  is  discharged  and  cooled  down,  and  a  silicate 
is  thus  obtained,  of  potash  or  soda,  according  to  which  alkali 
has  been  used  in  solution ;  and  this  solution  is  added  in  the 
proper  percentage  to  the  soap  paste  in  the  pan,  after  the 
saponification  is  complete,  and  before  it  has  cooled  down. 

Gui^-pifs  Process. — To  the  above  invention,  in  its  applica- 
tion to  ordinary  or  silicic  soaps,  a  gentleman  by  the  name  of 
Guppy  has  proposed  certain  improvements,  such  as  the  in- 
troduction of  stronger  lyes  and  in  separate  portions  into  the 
boiler  or  steam-tight  vessel,  to  be  injected  from  a  reservoir 
by  a  force-pump,  properly  appropriated  and  arranged,  and  in 
connection  with  both  the  boiler  and  reservoir.  For  every 
24  pounds  of  tallow,  10  pints  caustic  soda  lye,  of  17°  B.,  are 
added  to  the  boiler,  and  the  mixture  heated  to  148.9°  C. 
(300°  F.);  and  by  means  of  a  force-pump  about  30  pints  of 
soda  lye,  of  25°  B,,  to  every  24  pounds  of  tallow,  are  then 
injected  or  thrown  in,  and  the  mixture  maintained  for  two 
hours  at  148.9°  to  154.4°  C.  (300°  to  310°  F.).  At  the  end 
of  that  time  the  saponification  will  be  complete,  a  fact  deter- 


THE  FABRICATION  OF  SOAPS. 


333 


minable  by  drawing  out  samples  through  a  try-cock  fitted  in 
the  boiler  for  the  purpose.  The  stronger  lyes  are  kept  at  hand 
in  a  special  reservoir,  and  from  thence  drawn  by  the  pump, 
through  pipes  suitably  connected,  and  forced  in  through 
other  tubes.  The  advantages  gained  by  this  mode  of  opera- 
ting seem  to  be  a  saving  of  time  and  fuel;  but  whether 
these  expectations  are  to  be  realized  in  practice,  must  be 
determined  by  experiment. 

Davis's  Alkalumino  Silicic  Soap. — This  soap  is  a  patent  in- 
vention, by  which,  as  the  patentee  says,  the  cost  of  the  soap 
is  diminished,  whilst  its  detergent  and  normal  properties, 
instead  of  being  impaired,  are  much  improved.  The  plan 
consists  of  a  combination  of  fuller's  earth,  pipe-clay  and  pearl- 
ash,  with  the  soap  as  soon  as  it  is  poured  into  the  cooling 
frames.  When  pearlash  or  soda  is  employed,  it  is  necessary 
that  it  should  be  calcined  and  then  ground  together  with 
the  clay  and  earth  so  as  to  form  as  intimate  a  mixture  as 
possible.  In  this  mixed  state  it  is  incorporated  with  the 
soap.  To  every  126  pounds  of  soap  already  made  and  in  paste, 
take  56  pounds  of  fuller's  earth,  slaked  or  dried,  56  pounds  of 
dried  pipe-clay,  and  112  pounds  of  calcined  soda  or  pearl-ash, 
all  reduced  to  powder,  sieved  as  finely  as  possible,  and  tho- 
roughly incorporate  the  whole  by  stirring  or  crutching.  The 
mixing  must  be  very  perfect,  and  done  as  quickly  as  possible 
before  the  paste  soap  cools.  To  obviate  any  objection  against 
the  use  of  this  soap  for  washing  white  linens,  a  modification 
of  the  above  process  is  proposed,  by  which  the  use  of  fuller's 
earth  is  entirely  omitted,  leaving  the  proportions  then  for 
every  120  pounds  of  soap,  112  pounds  of  dried  pipe-clay,  and 
96  pounds  of  calcined  alkali.  A  soap  produced  by  these  quan- 
tities, the  patentee  says,  is  useful  for  general  purposes  at  sea, 
and  for  washing  white  linens  in  salt  water.  For  wasliing 
white  linens  in  fresh  water,  the  process  is  still  further  modified 
by  using  112  pounds  of  soap,  28  pounds  of  dried  pipe-clay, 
and  36  pounds  of  calcined  soda;  and  as  a  toilet  soap,  either 
for  fresh  or  salt  w^ater,  by  employing  28  pounds  of  fuller's 
earth,  slaked  or  dried,  and  20  pounds  of  calcined  soda  to  112 
pounds  of  perfumed  curd  soap. 


334  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Sand  Soap  is  made  with  the  admixture  of  fine  sand  to  the 
amount  of  20  or  25  per  cent,  in  weight,  which  is  best  added 
to  the  hot  soap  when  in  the  frames,  being  crutched  in  until 
the  soap  is  too  stiff  to  stir. 

Quartz  Soap  is  also  known  by  various  names,  as  diamond 
soap,  crystal  soap,  etc.,  and  is  made  by  crutching  into  the 
still  hot  soap  in  the  frames  about  20  per  cent,  of  finely  pow- 
dered quartz  or  spar,  as  in  the  manner  for  sand  soap. 

Poncein  Soap  is  also  a  useful  detergent  much  used  for 
cleaning  the  dirty  hands  of  those  engaged  in  mechanical 
trades.  The  process  is  the  same  as  for  sand  soap,  using  a 
very  finely  powdered  pumice  stone.  This  soap  is  also  made 
of  very  select  materials,  and  used  as  a  toilet  soap  with  the 
requisite  amount  of  perfume. 

For  the  mechanical  admixture  of  these  various  substances 
with  soap  there  are  a  number  of  new  crutching  machines 
that  greatly  facilitate  the  filling  of  all  soaps ;  we  have  illus- 
trated the  one  lately  invented  by  Mr.  Stephen  Strunz. 

Greaves  or  Crackling  Soap. — For  the  manufacture  of  this 
soap,  we  use  the  oftals  and  remnants  of  rendered  tallow, 
hogs'  lard,  etc. 

When  for  the  melting  of  the  tallow  sulphuric  acid  has 
been  employed,  the  greaves  must  at  first  be  washed  out  with 
water.  For  100  kilog.  (220  lbs.)  greaves  place  100  to  110 
kilog.  (220  to  242  lbs.)  of  20°  B.  soda-lye  in  the  kettle, 
which  is  to  be  heated  to  boiling,  and  leave  this  mass  to  rest 
for  48  hours,  during  which  time  the  greaves  dissolve  into  a 
gelatinous  mass.  The  boiling  is  then  continued  until  it 
becomes  pasty ;  add  cocoa-nut  oil  with  the  requisite  alkali 
to  it,  and  boil  until  it  becomes  a  paste  soap ;  after  the  dis- 
appearance of  froth,  or,  if  this  takes  too  long,  and  the  soap 
proves  to  be  firm,  it  is  run  into  the  frames,  after  previously 
skimming  off  the  froth. 

Bone  Soap. — By  this  name  we  designate  a  mixture  of  com- 
mon soap,  for  instance  tallow,  palm-oil,  or  rosin  soap,  which 
has  by  soda-lye  been  loosened  of  decomposed  ani malic 
gelatinous  matter  or  bones,  and  has  been  so  treated  that  a 
solid  mass  (soap)  is  produced.    With  regard  to  the  soap 


THE  FABRICATION  OF  SOAPS. 


335 


made  of  bones,  this  can  be  performed  by  two  difterent  methods. 
According  to  the  one,  the  bones  are  manipulated  with  con- 
centrated muriatic  acid,  and  they  need  not  be  previously 
broken  up.  This  acid  dissolves  the  carbonate  and  phosphate 
of  lime,  while  it  leaves  the  animal  gluten  as  a  strong  trans- 
parent mass,  in  the  form  of  the  bones.  By  repeated  washing 
it  is  entirely  freed  from  the  muriatic  acid;  this  gluten  is 
added  to  either  of  the  above-named  fats  during  the  process 
of  saponification. 

According  to  the  other  method  the  entire  mass  of  bones 
is  embodied  with  the  soap,  and  not  the  jelly  or  gluten  alone. 
For  this  purpose,  the  previously  bruised  bones  are  softened 
by  pouring  a  strong  caustic  lye  over  them  in  an  iron  vessel. 
The  lye  dissolves  the  gluten,  and  leaves'  the  earthy  paste  as 
a  residue,  in  the  shape  of  a  powder.  After  a  period  of  two  or 
three  weeks,  the  bones  are  perfectly  loosened  and  are  easily  re- 
duced to  a  pulp.  The  finely  ground  mixture  is  now  boiled  in 
the  kettle  for  one  hour,  in  order  to  saponify  with  this  caustic 
liquid  the  fat,  for  instance  cocoa-nut  oil,  in  the  same  manner 
as  is  done  with  common  lye.  Such  an  article  was  formerly 
produced  and  sold  under  the  name  "Liverpool  Poorman's 
Soap,"  and  much  used.  By  the  presence  of  the  gluten  and 
the  bone  clay,  the  soap  loses  but  little  of  its  firmness  and 
its  property  of  foaming.  It  shows,  however,  nothing  of  that 
which  is  termed  "^ram,"  and  it  appears,  when  cut,  of  dark- 
brown  color,  and  is  not  as  transparent  as  the  rosin  soaps. 

Other  Filled  Soaps. — By  a  change  of  the  proportions  between 
cocoa-nut  oil  and  the  other  fats  and  rosin,  and  these  again 
among  themselves,  and  by  applying  a  solution  of  salt-soda  or 
potash  for  the  filling  of  the  soaps,  the  number  of  the  variety 
of  these  filled  soaps  may  be  multiplied  indefinitely;  but  all 
of  them  resemble  each  other  in  this  one  particular,  that  of 
having  more  the  interest  of  the  manufVicturers  at  heart  than 
that  of  the  consumers,  and,  to  say  it  plainly,  they  are  in- 
ferior and  only  apparently  cheap.  The  following  are  a  few 
more  formulae  for  making  these  soaps: — 


336  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


I. 

Cocoa-nut  oil  

Palm-kernel  oil  .  .  .  . 
Crude  palm  oil       ...  . 

Tallow  

Caustic  soda-lye  28°  B.  . 
Solution  of  potash  25°  B. 
Salt  solution  25°  B.        .      .  . 

II. 

Cocoa-nut  oil         ,       .       .  . 

Tallow  

Caustic  soda-lye  20^  B.  . 
Solution  of  potash  30O  B. 
Salt  solution  250  B.       .       .  . 

Ill 

Cocoa-nut  oil  

Caustic  soda-lye  250  B.  . 
Solution  of  potash  120  B. 
Solution  of  potash  20o  B. 
Salt  solution  30o  B.  . 

IV. 

Cocoa-nut  oil  

Caustic  soda-lye  40o  B. 
Solution  of  potash  30o  B. 
Salt  solution  25^  B.       .       .  . 
Water   .       .  . 


2000  kilog.  (   4400  lbs.) 

2000  "  (   4400  "  ) 

630  "  (   1386  "  ) 

370  "  (     814  "  ) 

5350  "  (11,770  "  ) 

350  "  (     770  "  ) 

5200    "  (11,440  "  ) 


1000  kilog.  (22,000  lbs.) 
500  "  (  1100  "  ) 
960  "  (  2112  "  ) 
360    "     (     792   "  ) 

1680    "     (    3696   "  ) 


2720  kilog.  (  5984  lbs.) 

750          (  1650  "  ) 

1760    "     (  3872   "  ) 

960    "     (  2112   "  ) 

2000    "     (  4400   "  ) 


1680  kilog.  (  3696  lbs.) 

600    "     (  1323  ) 

800    "     (  660  ) 

860    "     (  1892   "  ) 

630    "     (  1386   "  ) 


NEW  SOAPS  BY  NEW  METHODS. 


337 


SECTION  XY. 

NEW  SOAPS  BY  NEW  METHODS. 

Innumerable  new  soaps  by  new  processes  are  constantly 
seeking  notice,  and  for  many  of  which  patents  are  granted 
nnore  for  their  novelty  than  for  their  intrinsic  merit,  for 
often  in  their  composition  they  set  at  defiance  all  chemical 
rules  and  are  worse  than  useless.  There  are,  however,  many 
others  that  being  based  on  science  may  be  considered  as  im- 
provements, and  have  a  useful  application  in  our  art. 

As  we  have  said,  there  are  many  other  means  of  saponifi- 
cation besides  soda  and  potash,  and  these  have  been  utilized 
to  decompose  the  neutral  fats,  for  various  uses  in  the  art. 
Yet,  in  as  far  as  a  detersive  soap  is  concerned,  they  have  not 
been  successful  in  practice.  But  for  making  the  stearic  acid 
for  candles  many  of  these  new  processes  have  found  a  practi- 
cal use.  Thus,  we  have  the  saponification  by  lime,  by  a 
small  portiofi  of  lime  assisted  by  surcharged  steam,  l>y  water 
and  distillation,  by  water  under  high  pressure,  by  sulphuric 
acid,  by  sulphate  of  soda,  etc.  When  we  come  to  treat  of 
the  manufacture  of  candles  these  processes  will  receive  that 
attention  which  they  deserve.  Yet,  there  are  some  of  these 
processes  that  here  claim  our  attention  and  are  of  interest. 

Saponification  of  Fats  by  means  of  Carbonated  Alkalies,—^ 
Under  ordinary  conditions,  the  carbonated  alkalies  do  not 
possess  the  power  to  separate  the  glyceryl  oxide  from  the 
neutral  fats,  and  to  combine  with  the  sebacic  acids.  By  an 
increased  temperature,  however,  a  lively  reaction  ensues, 
whereby  the  carbonated  alkali  does  lose  its  carbonate,  while 
the  sebacic  acid  and  the  base  combine  for  a  real  soap.  When, 
for  instance,  a  mixture  of  100  parts  tallow  and  22  to  25  parts 
anhydrous  carbonate  of  soda  is  gradually  heated,  vigorous 

22 


338 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


action  takes  place,  at  260^  C.  (500^  F.),  and  the  mixture 
becomes  much  puffed  up,  in  consequence  of  a  great  develop- 
ment of  carbonic  acid  gas.  Towards  the  end,  the  tempera- 
ture must  be  somewhat  increased,  in  order  to  decompose  the 
last  portions  of  neutral  fat. 

After  a  few  hours  a  semi-liquid,  yellowish  mass  is  obtained, 
which,  during  its  cooling  off,  becomes  more  consistent.  In 
water  it  dissolves  gradually  to  an  opalescent  liquid,  which  in 
every  respect  acts  like  a  solution  of  common  soap.  The  car- 
bonated alkalies,  as  also  culinary  salt,  cause  therein  a  separa- 
tion of  soda-soap,  which  collects  upon  the  surface  of  the 
liquid. 

Saponificaiion  of  Fats  by  Sulphuretted  Alkalies. — This  method 
has  been  proposed  by  Pelouze.  Despite  this  authority,  we 
have  not  been  able  to  discover  in  this  new  method  any  special 
advantage;  for  although  an  equivalent  of  sulphide  of  so- 
dium, where  this,  like  the  soda,  is  produced  on  a  large  scale, 
may  be  cheaper  than  an  equivalent  of  caustic  soda,  there 
are  nevertheless  other  inconveniences  which  are  much  greater, 
since  the  alkalies  form  in  themselves  a  proportionately  cheap 
ingredient  of  the  soap,  and  there  is  therefore  caused,  by  the 
cheaper  sulphide  of  sodium,  no  essential  reduction  in  the 
prices  of  the  soaps. 

In  the  practical  performance,  the  fats  are  treated  in  ex- 
actly the  same  manner  with  a  solution  of  sulphide  of  sodium, 
as  the  common  method  with  soda-lye.  The  saponification 
ensues  by  means  of  sulphide  of  sodium  very  quickly  and 
under  a  development  of  sulphuretted  hydrogen  gas,  which, 
on  account  of  its  very  disagreeable  smell  and  its  poisonous 
properties,  must  be  made  harmless.  Tliis  may  be  done  most 
advantageously  by  burning  it,  and  the  sulphurous  acid  which 
is  produced  by  the  process  of  burning  may  be  applied  in  the 
fabrication  of  sulphuric  acid.  But  this  presupposes  a  very 
extensive  and  complicated  business,  such  as  would  hardly  he 
suitable  for  many  soap-manufactories.  Moreover, according  to 
Dullo,  the  soap  made  with  sul[)hide  of  sodium  retains  a  had 
smell,  which  cannot  be  removed,  and  finally  the  manufacture 
of  white  soaps  with  sulphide  of  sodium  would  become  en- 


NEW  SOAPS  BY  NEW  METHODS. 


339 


tirely  impossible,  on  account  of  the  unavoidable  admixture 
of  coloring  substances. 

'  Tke  Process  of  Mege  Mouries — This  process  requires  a  par- 
ticular notice  here,  as  when  first  made  known  it  attracted 
great  attention,  which  has  however  subsided,  though  it  has 
resulted  in  suggestions  which  have  been  utilized  particularly 
in  France,  especially  for  making  the  sebacic  acids  in  the 
manufacture  of  candles.  He  found  that  the  neutral  fats  in  the 
oil  seeds  during  germination,  as  well  as  in  the  animal  organism 
during  life,  are  in  the  condition  of  movable  globules,  which 
ofifer  a  great  surface  to  the  action  of  reagents.  In  this  globular 
state,  fats  exhibit  some  peculiar  properties  of  which  we  shall 
only  notice  such  as  are  interesting  to  the  soap-maker.  Fat, 
as  for  example  tallow,  in  the  ordinary  state,  becomes  rancid  by 
exposure  to  the  air;  in  the  globular  state,  in  a  milky  form, 
or  in  a  dry  state,  or  in  the  form  of  a  white  powder,  it  remains 
unaltered  any  length  of  time.  In  practice  it  is  obtained  by 
mixing  melted  tallow  at  45°  C.  (113°  F.)  with  water  at  the 
same  temperature,  holding  in  solution  5  to  10  per  cent,  of 
soap.  It  is  difiicult  to  combine  tallow,  in  its  ordinary  state, 
with  hot  salty  caustic  lyes ;  but  in  the  globular  state  the  lye 
is  immediately  absorbed  in  ])r()portions  varying  with  the 
temperature.  Each  globule,  as  it  is  attacked  by  the  alkali, 
quickly  gives  up  its  glycerine,  and  in  a, very  short  time  each 
globule  of  fat  is  transformed  into  a  globule  of  perfect  soap. 
This  result  is  obtained  in  two  or  three  hours.  These  saponi- 
fied globules  heated  to  60°  C.  (140°  F.)  give  up  the  excess 
of  lye  with  which  they  are  charged,  and  retain  only  water 
sufiicient  for  ordinary  soap.  They  become  eventually  trans- 
parent, and  by  stirring  form  a  layer  of  melted  soap  above 
the  lye.  The  saponification  is  so  complete,  that  to  prepare 
commercial  stearic  acid,  it  is  only  necessary  to  add  a  cor- 
responding quantity  of  diluted  sulphuric  ncid,  and  the  fatty 
acids  may  be  separated  from  the  solution  of  sulphate  of  soda. 
By  melting  with  steam,  crystallizing  and  pressing  when 
cold,  a  conmiercial  stearic  acid  is  obtained  perfectly  pure, 
melting  at  from  57.7°  to  58.8^  C.  (136^  to  138^  F.),  while  the 
oleic  acid  flows  off  nearly  colorless.    This  latter  acid  is  of  a 


340  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


better  quality  than  many  fixed  oils,  and  more  useful  to  manu- 
facture white  soap  of  first  quality  either  alone  or  mixed  with 
some  other  fatty  substances.  By  using  it  alone,  it  has  only  to 
be  neutralized  by  weak  lyes;  the  formation  of  the  soap  takes 
place  immediate!}^,  and  it  can  be  melted  at  once.  If  mixed 
with  some  other  fat,  this  fat  has  to  be  transformed  into  the 
globular  state  and  the  saponification  is  eft'ected  in, six  hours; 
and  in  twenty-four  hours  a  soap  may  be  prepared  which  is  as 
neutral  and  nearly  as  good  as  the  best  olive  oil  soap.  Thus 
not  only  is  time  saved,  but  there  is  no  loss  of  fat  as  in  the 
ordinary  process  of  boiling  soap. 

Knapp  attributes  the  great  efficacy  of  the  globular  state 
not  so  much  to  the  globular  form  as  to  the  microscopic  size 
of  the  tallow  globules,  which  may  be  attacked  to  their  centre 
by  the  lye,  while  a  large  lump  of  tallow,  under  the  same 
circumstances,  would  soon  be  coated  with  a  stratum  of  soap 
of  a  thickness  which  would  render  it  impossible  to  penetrate 
it.  As  to  the  saponification  in  the  kettle,  there  is,  strictly 
speaking,  only  an  emulsion  of  fat  obtained,  a  homogeneous 
milky  mass,  formed  by  the  union  of  the  melted  tallow  with 
the  lye;  moreover,  soap  is  simultaneously  produced  by  the 
first  contact  of  these  substances.  This  emulsion,  after  stand- 
ing a  few  hours  in  the  cold,  becomes  gradually  saponitied. 
It  might  be  expected  that  the  process  would  be  more  rapid 
under  the  influence  of  heat  and  agitation,  but  this  is  not  the 
case,  and  the  hypothesis  is  that,  in  the  boiling,  each  fat  glob- 
ule is  immediately  enveloped  in  a  coating  of  stearate  of  soda, 
which  protects  the  nucleus  from  further  saponification.  In 
like  manner,  and  upon  the  same  principle,  heated  soap  bub- 
bles are  only  denuded  of  their  gelatinous  coating,  and  the  mass 
becomes  a  thickish  soap  solution  rather  than  a  chemical  com- 
pound. 

Again,  concentrated  soap  in  the  heated  mass  will  retain  a 
considerable  quantity  of  fat  in  solution,  consequently  dimin- 
ishing the  action  of  the  alkali.  This  may  be  remedied  by 
the  addition  of  a  middling  strong  lye  ;  but  in  any  case,  cool- 
ing and  quiet  are  found  to  promote  the  combination  of  fat 
with  alkalies,  after  having  been  heated  for  a  sufficient  length 


NEW  SOAPS  BY  NEW  METHODS. 


341 


of  time  to  effect  as  minute  a  division  of  the  molecules  as 
possible  in  the  characteristic  form  of  an  emulsion.  For  this 
jturpose  a  temperature  greater  than  48.9°  C.  (120°  F.)  is  not 
required. 

Perutz  affirms  that  the  facts  discovered  by  Mege  Mouries 
have  been  successfully  applied  in  soap  making.  "  To  every  ra- 
tional nanufacturer,"  he  says,  "it  must  be  known  that  sapon- 
ification is  produced  with  greater  ease  when  the  fat  is  stirred 
for  about  an  hour  under  a  slight  heat — about  60°  C.  (140°  F.) 
— with  the  so-called  combination  lye,  and  suffered  to  remain 
undisturbed  for  one  night."  As  this  mixture  never  reaches 
the  boiling  point,  it  follows  that  the  globular  emulsive  state 
must  be  produced  and  saponification  expedited. 

With  the  view  of  improving  this  discovery,  and  shorten- 
ing the  time  of  boiling,  Perutz  proposes  to  add  to  the  fat  the 
whole  quantity  of  lye  necessary  for  the  saponification,  and 
then  proceed  according  to  Mege  Mouries'  plan,  leaving  the 
mixture  quiet  all  night.  Until  now,  soap  boilers  have  not, 
at  the  beginning,  added  the  entire  quantity  of  lye  required, 
because  experience  has  shown  that  saponification  is  thereby 
rendered  more  difficult;  but,  on  the  other  hand,  it  has  also 
been  ascertained  that  the  saponification  is  more  rapidly  ef- 
fected at  a  low  temperature.  Whether  this  process  of  fabri- 
cating soap,  as  Mege  Mouries  asserts,  is  essentially  cheaper 
than  the  usual  method,  could  only  be  decided  by  experiment 
on  a  large  scale,  but  that,  if  we  work  only  with  pure  mate- 
rials, a  very  beautiful  pure  soap  is  obtained,  we  have  satisfied 
ourselves  by  experiments. 

Methods  of  M.  D'Arcet. — These  suggestions  have  an  interest 
here  as  they  throw  some  light  on  our  subject  and  have  a  scien- 
tific basis,  and  may  be  a  guide  to  new  methods.  He  remarks, 
there  are  two  very  distinct  operations  in  the  fabrication  of 
soaps;  the  first  has  for  its  object  to  chemically  combine  the 
alkali  with  the  fatty  bodies,  while  in  the  second,  the  formed 
eoap  must  be  made  to  contain  the  j)roper  quantity  of  water, 
by  the  processes  of  liquefaction  or  mottling  if  a  white  soap 
containing  50  per  cent,  of  water,  or  a  marl)led  soap  contain- 
ing only  33  per  cent,  is  to  be  manufactured. 


342  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


The  first  operation,  called  saponification,  presents  numer- 
ous (lifiiculties;  it  is  important  to  add  to  the  fatty  body  the 
necessary  caustic  lye,  little  by  little,  and  of  a  proper  density, 
so  that  the  soap  when  formed  will  not  dissolve  in  the  liquor, 
nor  be  transformed  into  too  large  and  too  hard  grains.  If 
the  soap  dissolves  in  the  boiling  lye,  the  whole  will  soon 
form  a  mass,  the  soap  will  burn  at  the  bottom  of  the  kettle, 
and  the  operation  thus  conducted  will  be  impossible.  If,  on 
the  contrary,  the  saponification  is  effected  by  using  too  much 
of,  or  too  concentrated  a  lye,  the  ebullition  will  with  diffi- 
culty bring  about  a  sufficient  contact  between  the  fatty  bodies 
and  the  lye,  which  will  retard  the  saponification,  and  in- 
crease the  expense  in  fuel,  work,  etc. 

The  necessity  of  keeping  the  soap  during  all  the  time  of 
the  saponification  in  a  state  of  half  solution  in  the  boiling 
lye,  presents  great  difficulties  of  execution,  and  renders  the 
operation  much  longer  and  too  costly. 

The  saponification  being  finished,  the  soap  is  boiled  down, 
that  is,  until  the  lye  on  which  the  soap  floats  is  concentrated 
by  evaporation  to  the  density  at  which  the  grain  contains 
just  the  necessary  quantity  of  water.  It  is  thus,  that  after 
the  saponification,  the  soap  contains  more  than  50  per  cent, 
of  water,  while  towards  the  end  of  the  coction  the  grain  of 
soap  contains  only  about  16  per  cent. 

This  operation  has  for  its  principal  object  to  leave  in  the 
grain  of  the  soap  only  the  proper  quantity  of  lye,  but  it  pre- 
sents at  the  same  time  the  advantage  of  completing  the 
saponification,  if  this  first  operation  has  not  already  been 
completely  effected,  and  besides,  of  rendering  the  soap  homo- 
geneous in  all  its  parts.  After  the  coction  of  the  soap  comes 
its  liquefaction,  if  it  is  to  be  converted  into  white,  or  its 
mottling,  if  it  is  to  be  manufactured  into  marbled  soap. 

The  liquefaction  or  fitting  has  for  its  object  to  soften  the 
grain  of  the  soap,  to  introduce  into  it  as  much  as  55  per 
cent,  of  water,  instead  of  the  16  per  cent,  that  the  coction 
has  left  in  it,  to  render  the  paste  nearly  liquid,  and  to  favor 
thus,  during  the  cooling  of  the  soap  in  the  frame,  the  precipi- 
tation of  all  foreign  substances  that  the  grains  may  contain, 


NEW  SOAPS  BY  NEW  METHODS. 


which  contributes  to  bleach  this  kind  of  soap,  and  to  give  it 
much  homogeneity^,  and  a  great  degree  of  purity. 

As  for  the  marbling  of  the  soap,  it  might  be  improved.  It 
is  true  that  soap  has  been  marbled  at  Marseilles  for  many 
years,  and  when  the  art  of  soap-making  is  well  understood  it 
strikes  me  that  since  the  origin  of  the  art,  the  manufacturers 
have  obtained  soaps  more  or  less  well  marbled. 

At  the  time  of  the  saponification,  the  iron  which  is  held 
in  solution  in  the  lye  of  sulphuretted  soda  combines  with  the 
fatty  bodies  and  the  iron  of  the  kettle,  and  forms  a  soap  of 
iron,  and  the  manufacturer  is  often  obliged  to  add  some 
green  vitriol;  on  the  other  hand,  the  alumina  and  lime  con- 
tained in  the  lyes  are  also  converted  into  soaps  of  alumina 
and  lime,  and  these  three  soaps  dissolve  in  the  nearly  liquid 
mixture  of  oil  and  soap  submitted  to  the  saponification. 

Later,  when  the  saponification  is  finished,  and  even  at  the 
end  of  the  coction,  the  soaps  of  iron,  lime,  and  alumina  are 
so  uniformly  divided  in  the  mass,  that  it  may  be  said  that 
they  are  in  a  state  of  true  solution.  They  color  it  a  gray- 
ish-blue in  all  its  parts,  if  the  lye  on  which  the  soap  boils 
has  not  ceased  to  be  sulphuretted;  and  the  soap,  suddenly 
cooled  and  cut  into  thin  plates,  looks  then  like  damp  slate. 

The  soap,  being  finished  and  colored  as  we  have  just  stated, 
is  too  dry  on  account  of  the  high  density  of  the  boiling  lyes 
on  which  it  floats.  It  must  be  brought  back  to  contain  at 
the  most  36  per  cent,  of  water.  This  is  done  by  the  operation 
called  mottling,  which  has  for  its  object  to  swell  and  soften 
the  grains  of  soap.    (See  Marseilles  Soap.) 

When  this  is  done,  the  mass  of  soap  ought  to  be  evenly 
penetrated  with  water  throughout;  the  grains  must  be  soft 
and  voluminous, hardly  separated  from  the  warm  lye  on  which 
they  float,  and  the  greater  part  of  which  is  interposed  between 
the  grains  of  soap  properly  softened.  The  soap  is  then  run 
into  the  frame,  and  the  operation  is  finished.  Let  us  see  what 
takes  place  in  the  frame. 

If  the  soap  is  run  into  a  thin  dish,  and  if  a  portion  of  the 
soap,  taken  at  the  time  it  is  run  into  the  frame,  is  quickly 
cooled  down,  a  soap  uniformly  colored  blue  like  damp  slate 


344  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


is  obtained  ;  the  soap  then  is  not  marbled  at  the  time;  the 
mixture  of  the  soaps  of  iron,  alumina,  and  lime,  colored  by 
sulphuretted  lye,  is  still  in  solution  in  the  mass,  but  by  de- 
grees, and  by  the  progressive  cooling, the  soaps  of  alumina  and 
lime,  being  less  soluble  and  less  fusible  than  the  soap  of  soda, 
separate  and  divide  in  the  mass  of  soap,  which  is  white  for  the 
greater  portion,  but  is  streaked  with  strongly  colored  runs, 
which  are  formed  by  those  portions  of  the  soap  in  which  has 
concentrated  the  mixture  of  the  soaps  of  iron,  lime,  and  alu- 
mina, colored  blue  by  the  action  of  the  sulphuretted  lye. 

The  marbling  of  the  soap  is  not  an  effect  produced  by  a 
simple  mechanical  mixture  of  two  soaps,  one  of  which  is  col- 
ored ;  the  cause  which  controls  its  formation  belongs  to  a  more 
elevated  order,  for  the  separation  of  soaps  having  different 
bases,  during  the  cooling  in  the  frame,  is  effected  by  the  ac- 
tion of  that  force  which  separates  alloys  at  the  time  of  their 
solidification,  the  effect  of  which  is  known  by  the  name  of 
liquation ^'dv^ii  to  which  we  attribute  the  formation  of  granites, 
etc.,  and  in  genera),  that  of  all  the  primitive  crystallized 
rocks. 

In  the  fabrication  of  the  bar  soap  by  using  sulphuretted 
lyes,  a  white  soap  is  obtained,  because  the  liquefaction  is 
carried  to  the  point  where  the  paste  is  fluid  enough  to  permit 
the  whole  of  the  blue  colored  soaps  of  iron,  alumina,  and  lime 
being  heavier  to  separate  completely  and  fall  to  the  bottom  of 
the  kettle. 

The  mixture  of  soaps  of  iron,  alumina,  and  lime,  dissolved 
in  ordinary  soap,  and  colored  by  the  action  of  the  sulphuretted 
lye,  quickly  loses  its  color  in  the  air  under  the  influer)ce  of 
water  and  the  excess  of  alkali  the  soap  contai)is;  the  blue 
color  by  disappearing  leaves  a  yellow  trace,  so  much  darker 
wdien  there  is  more  iron  in  thesoap,  which  is  d  ne  to  this,  that  the 
mixture  of  the  soaps  of  iron,  alumina,  lime,  and  soda,  being 
desulphuretted,  is  colored  only  by  the  iron  soap  which  has 
an  ochreous  yellow  color.  These  yellow  lines  are  not  wanted 
by  the  consumer,  and  they  result  in  a  loss  to  the  soap-maker. 
It  is  required  that  the  soap  shall  have  a  marbling  of  a  line 


NEW  SOAPS  BY  NEW  METHODS. 


345 


dark  blue,  and  that  the  part  of  the  soap  thus  shaded  shall 
become  red  in  the  air,  by  absorption  of  oxygen. 

In  conclusion,  for  the  marbling  of  soap,  the  following  con- 
ditions have  to  be  fulfilled  : — 

1.  To  have  in  the  mass  the  quantity  of  iron  soap  necessary 
to  give  the  required  degree  of  coloration. 

2.  That  the  iron  soap  shall  be  combined  with  a  suiRcient 
quantity  of  soap  of  lime  and  alumina,  so  as  to  produce  a 
transparent,  homogeneous,  and  properly  shaded  marbling. 

3.  To  have  all  the  time,  but  especially  at  the  end  of  the 
coction,  a  proper  excess  of  sulphuretted  lye  in  contact  with 
the  soap. 

4.  That  the  cooling  in  the  frame  is  managed  in  such  a 
manner  as  to  produce  the  required  marbling. 

Instead  of  saponifying  with  weak  lyes,  and  in  deep  and 
conical  kettles,  I  operate  in  large  sheet-iron  vats  being  three 
times  as  long  as  they  are  wide,  heated  below  only  by  the 
waste  heat  of  the  ordinary  kettles,  and  I  use  strong  caustic 
lyes  containing  a  little  common  salt,  instead  of  using  weak 
lyes  and  gradually  increasing  their  density. 

The  heat  communicated  to  the  vats  is  not  above  50^  C. 
(122°  F.),  and  may  be  sufficient  only  to  keep  the  fatty  body 
perfectly  liquid. 

Instead  of  stirring  the  mixture  by  ebullition,  I  use  a 
mechanical  stirrer  conveniently  fixed,  which  multiplies,  more 
economically  than  the  ebullition,  the  points  of  contact  be- 
tween the  fatty  body  and  the  lye.  The  stirring  is  continued 
until  the  chemical  combination  which  constitutes  the  soap  is 
completed,  which  is  ascertained  l)y  the  strength  of  the  lye, 
which  must  remain  the  same,  and  the  complete  solubility  of 
the  soap  in  boiling  water.  The  soap  is  then  converted  into 
small  round  grains  without  adherency,  and  swimming  on 
the  excess  of  caustic  lye;  the  saponification  is  then  finished. 

The  vat  in  which  this  operation  takes  place  has  its  edges 
elevated  about  three  feet  above  the  large,  deep,  and  conical 
kettle  in  which  the  coction  is  finished.  A  wooden  gutter  is 
used  to  transfer  the  soap  from  the  vat  into  the  kettle;  the 
old  lye,  remaining  in  the  bottom  of  the  vat,  is  drawn  ofl:*,  and 


346 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


a  new  operation  may  be  begun.  As  for  the  soap  in  grains 
which  has  been  introduced  into  the  hirge  kettle  with  new 
lye,  its  saponification  is  completed,  and  the  coction  is  con- 
ducted as  usual;  it  is  also  converted  into  white  or  marbled 
soap. 

To  manufacture  white  soap,  it  is  not  necessary  to  add 
coloring  matter  ;  but  for  the  marbled  soap,  the  mass  must  be 
colored  in  the  vat  at  the  beginning  of  the  saponification. 

This  coloration  is  managed  as  follows: — 

In  a  kettle,  I  prepare  a  mixture  of  soaps  of  alumina,  lime, 
and  lead,  by  decomposing  in  the  order  indicated  below,  by 
an  excess  of  soap  dissolved  in  water,  solutions  of  acetate  of 
lead,  chloride  of  calcium,  and  alum.  The  mixture  obtained 
is  kept  under  water,  and  is  used  to  color  marbled  soap,  which 
is  done  by  adding  at  the  beginning  of  the  operation  enough 
of  the  mixture  to  give  to  the  mass  the  proper  shade.  The 
sulphuretted  lye  used  in  the  saponification  quickly  gives  to 
the  soap  of  lead  the  blackish-blue  color  necessary  to  color  the 
marbling,  and  consequentlj^,  it  is  easy  by  diflferent  trials  to 
obtain  the  required  shade. 

What  we  have  said  of  the  marbling  of  soap,  proves  that 
there  is  a  necessary  relation  between  the  beauty  or  the  per- 
fection of  the  marbling  of  the  soap,  and  the  quantity  of 
water  it  contains.  A  well-marbled  soap  cannot  contain  more 
than  33  to  34  per  cent,  of  water,  while  white  soap  may  re- 
ceive more  without  losing  its  good  appearance,  and  it  is 
even  whiter  when  it  contains  more  water.  To  manufacture 
white  soap  containing,  like  the  marbled  soap,  33  per  cent,  of 
water,  lyes  free  from  sulphides  must  be  used,  which  may 
increase  the  expense  of  fabrication.  We  have  noticed  this 
fact,  because  it  is  generally  believed  that  the  preference  given 
to  marbled  soap  is  ridiculous  and  without  foundation,  while 
on  the  contrary,  this  preference  is  the  result  of  a  long  ex- 
perience. 

Soaps  by  Steam  Pressure. 

In  the  processes  for  making  soap  by  pressure  and  by  agita- 
tion, using  carbonated  alkalies,  we  would  call  attention  to 


NEW  SOAPS  BY  NEW  METHODS. 


347 


848  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


the  two  together,  for  which  they  took  out  a  patent  in  1865. 
Their  process  consists  in  agitating  the  saponifiable  materials 
with  caustic  or  carbonated  alkalies  in  solution  in  water  in  a 
closed  vessel  while  under  heat  and  pressure,  in  such  a  manner 
as  to  cause  a  thorough  mixing  of  the  fats  with  the  alkaline 
solution,  and  producing  an  instantaneous  combination  of  the 
fatty  acids  with  the  base  of  the  alkaline  solution. 

We  suppose  a  quantity  of  fatty  matter  inclosed  in  a  vessel 
with  a  solution  of  carbonate  of  soda  in  water,  and  heat 
applied  to  produce  a  pressure  of  220  to  280  pounds  per  square 
inch,  and  atemperatureof  176.6^  to  204.4°  C.  (350°  to  400°  F.). 
A  combination  between  the  fatty  acids  and  the  soda  of  the 
solution  will  take  place  only  at  the  upper  surface  of  the  solu- 
tion when  in  contact  with  the  under  surface  of  the  grease, 
the  heavy  lye  occupying  the  lower  part  of  the  vessel,  and 
soap  will  only  be  produced  when  the  fat  and  alkali  unite. 
If  we  now  agitate  in  such  a  manner  as  to  stir  together  and 
thoroughly  mix  the  contents  of  the  vessel,  the  whole  will  be 
instantly  converted  into  a  homogeneous  and  even  quality  of 
soap.  It  is  advisable  to  use  no  more  water  than  is  wanted 
in  the  soap. 

The  inventors  use  a  boiler  or  cylinder  similar  in  shape  to 
a  plain  cylinder  steam  boiler,  resting  horizontally  and  heated 
in  any  convenient  manner;  one  or  both  heads  of  the  cylin- 
der is  made  so  as  to  be  removable,  and  is  about  the  full 
size  of  the  inner  diameter  of  the  cylinder,  so  as  to  admit 
of  the  insertion  of  a  revolving  shaft  a  a  a  (Fig.  61),  which 
should  be  as  long  as  the  cylinder  itself.  The  bearings  of  this 
shaft  should  be  in  the  centre  of  the  cylinder,  and  either  or 
both  ends  worked  through  a  stuffing  box  for  the  conveni- 
ence of  applying  to  the  pulley  A,  power  to  revolve  the  shaft.  On 
the  shaft  are  fastened  arms  g  with  floats  /,  or  stirrers,  ex- 
tending nearly  to  the  sides  of  the  cylinder;  the  arms,  floats, 
or  iigitators  on  one  side  of  the  shaft  when  revolved  carry  the 
fat  down  into  the  alkali,  wiiile  the  agitators  on  the  other 
side  carry  the  alkali  up  into  the  fat,  thus,  while  under  heat 
and  pressure,  thoroughly  mixing  the  whole  and  causing  the 
conversion  of  the  wdiole  contents  of  the  vessel  instantly  into 


NEW  SOAPS  BY  NEW  METHODS. 


349 


a  uniform,  even,  and  good  quality  of  soap.  At  the  fire  end 
of  the  cylinder  are  placed  two  safety  valves,  one  on  the 
top  of  the  cylinder,  the  other  on  an  outlet  pipe  inserted  in 
the  head  of  the  cylinder ;  they  also  use  a  mercury  bath  A*,  of 
about  four  inches  in  length  of  gas  pipe,  and  which  is  screwed 
into  the  boiler  or  cylinder  in  any  convenient  place  for  the 
insertion  of  the  thermometer  bulb.  At  the  opposite  end  of 
the  cylinder  is  an  opening  r,  for  the  insertion  of  a  supply 
pipe ;  at  the  fire  end  is  also  an  opening  ^,  for  the  insertion  of 
a  second  outlet  pipe,  and  which  is  intended  to  be  used  only 
when  it  is  desired  to  draw  off  the  whole  contents  of  the  cyl- 
inder. The  contents  of  the  cylinder  when  operated  upon 
should  be  subjected  to  a  pressure  of  about  220  to  280  lbs.  per 
square  inch,  and  under  a  heat  of  about  176.6^  to  201.4°  C. 
(350°  to  400°  F.  ). 

When  the  shaft  is  revolved,  all  of  the  ingredients  in  every 
part  of  the  cylinder  are  immediately  and  thorouglily  mixed, 
and  the  same  will  take  place  by  means  of  any  other  revolv- 
ing machinery.  Perfect  saponification  is  at  once  effected,  and 
the  soap  produced  is  of  uniform  and  good  quality.  When 
the  machinery  is  first  put  in  operation,  it  is  necessary  to 
allow  some  carbonic  acid  gas  to  escape  by  one  of  the  safety 
valves,  if  carbonate  of  soda  is  used,  in  order  to  prevent  un- 
due pressure  by  the  liberation  of  the  carbonic  acid  when 
combination  of  the  fatty  acids  with  the  alkali  takes  place. 
If  any  of  the  liquids  be  allowed  to  escape  before  the  tem- 
perature reaches  162.7°  to  190.5°  0.  (325°  to  375°  F.),  they 
should  be  returned  to  the  cylinder. 

The  safety  valve  on  the  outlet  pipe  may  be  so  loaded  as 
to  allow  an  escape  of  soap  at  a  pressure  of  250  to  270  lbs., 
and  a  quantity  of  lye  and  oil  may  be  pumped  in  at  the  oppo- 
site end,  the  agitation  by  the  revolving  shaft  being  still  kept 
up,  and  thus  a  continual  stream  of  soap  is  kept  u|)  as  long 
as  the  feeding  is  continued.  The  product  may  then  l)e  pre- 
pared for  market  by  the  cooling,  moulding,  and  cutting  pro- 
cesses in  ordinary  use. 

By  this  process  the  soap  is  made  in  less  than  one  hour 
from  the  time  the  ingredients  are  introduced  into  the  boiler, 


350 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


but  a  uniform  and  thorough  saponification  is  obtained  at  the 
instant  that  the  heat  and  pressure  arrive  at  the  required 
degree,  be  the  time  long  or  short;  if  this  degree  is  reached 
in  five  minutes,  the  soap  is  made. 

The  inventors  use  from  30  to  33  lbs.  of  carbonate  of  soda 
at  — 48°,  and  100  lbs.  water  to  100  lbs.  of  lard,  tallow,  or  oil ; 
27  lbs.  of  carbonate  will  make  a  neutral  soap  for  soft  water. 
The  product  obtained  is  200  lbs.  of  soap  for  every  100  lbs.  of 
grease. 

Any  kind  of  soap  can  be  made  by  this  process;  soft  soap 
is  prepared  with  the  same  rapidity  as  an}^  other,  and  is  much 
more  perfect  and  requires  a  less  quantity  of  potash  than  by 
the  open  kettle  process;  four  lbs.  of  potash  being  required 
for  one  barrel. 

To  conclude,  we  would  state  that  the  advantages  claimed 
for  this  process  are: — 

1.  The  rapidity  of  manufacture.  2.  The  improvement  in 
quality.  3.  The  increased  quantity.  4.  Economy  in  labor. 
5.  Saving  of  fuel.  6.  The  use  of  clieaper  material.  7.  The 
saponification  of  all  the  grease.  8.  The  uniform  certainty 
of  the  results.  9.  The  saving  of  the  valuable  property  of 
glycerine  which  greatly  improves  the  quality  of  the  soap. 
10.  The  ability  to  use  alkaline  salts  instead  of  caustic  lye, 
obviating  the  necessity  of  using  chloride  of  sodium,  which 
is  required  by  the  common  process,  in  order  to  get  rid  of  the 
waste  lye. 

Professor  Dussauce  examined  some  specimens  of  soap  made 
by  this  process,  and  found  them  perfectly  neutral,  and  entirely 
saponified,  without  a  trace  of  carbonated  alkali,  and  not  con- 
taining as  much  water  as  soap  made  by  the  ordinary  process. 


SOAP  ANALYSIS. 


851 


SECTION  XYI. 

SOAP  ANALYSIS. 

There  are  few  articles  of  industry  or  commerce  that  are 
subject  to  so  much  falsification  as  soap,  and  it  is  partly  be- 
cause the  public  ignorantly  wish  a  cheap  one,  hence  there  is 
always  a  desire  to  find  a  suitable  and  often  an  unsuitable 
substitute  with  which  to  adulterate  it,  to  enhance  the  profits 
of  unprincipled  makers. 

There  are  many  methods  of  analyzing  and  appraising  soaps, 
but  they  are  not  so  easy  or  simple  that  every  one  can  per- 
form them  with  the  necessary  accuracy.  Soaps  differ  accord- 
ing to  their  value  in  alkali  and  to  their  organic  ingredients, 
i.  e.,  fat  and  rosin.  Thus  in  the  valuation  of  soap  we  have 
to  consider:  1st.  Tlie  contents  of  water ;  2d.  The  proportion 
of  sebacic  acids  to  the  alkali ;  3d.  The  nature  of  the  alkali 
and  of  the  sebacic  acid  ;  4th.  The  intentional  or  unintentional 
admixture  of  foreign  substances. 

Although  the  amount  of  water  in  a  hard  soap  appears 
easily  determined,  it  is  nevertheless  a  somewhat  difiicult 
matter.  This  is  easily  seen  when  we  know  that  each  part 
of  a  cake  or  bar  of  soap  contains  a  different  amount,  the  outer 
part  being, denser  than  the  centre,  so  a  sample  for  testing 
should  be  a  mixture  of  all  parts  to  make  an  average.  The 
sample  obtained  is  to  be  scraped  fine,  the  different  parts  uni^ 
formly  mixed,  and  from  this  the  quantity  to  be  investigated 
weighed  off;  both  operations,  of  mixing  and  weighing,  must 
be  carried  out  quickly  so  that  the  soap  can  neither  absorb  nor 
lose  water.  The  sample,  say  about  10  grammes  scraped  soap, 
is  placed  in  a  small  porcelain  saucer,  weighed,  and  placed 
over  a  water-bath  and  heated  until  the  soap  no  longer  loses 
in  weight.    At  first  the  soap  is  left  entirely  untouched,  and 


352  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


only  when  it  has  passed  from  the  liquid  into  the  pasty  state 
the  lumps  are  pressed  with  a  glass  spatula  which  has  pre- 
viously been  weighed.  If  the  two  last  weighings  correspond, 
the  soap  is  removed  and  weighed,  and  the  loss  is  the  weight 
of  the  water  contained  in  the. soap. 

Determination  of  the  Amount  of  Alkali, — For  this  purpose 
it  is  well  to  use  the  dry  soap  left  b}^  the  determination  of 
the  amount  of  water.  This  is  placed  in  a  glass  flask,  the 
porcelain  saucer  and  glass  spatula  are  repeatedly  washed  olF 
in  strong  alcohol,  putting  all  the  liquid  of  the  rinsing  opera- 
tion into  the  flask,  then  add  from  50  to  60  cubic  centimetres 
(1.69  to  2.03  fl.  ozs.)  of  the  strongest  alcohol,  the  whole  heated 
in  a  water-bath  putting  the  stopper  loosely  on.  The  soap 
is  dissolved,  allowed  to  precipitate,  and  to  cool  off.  The 
liquid,  having  cleared  ofi:'  perfectly,  is  decanted  carefully  into 
another  larger  flask.  Pour  over  the  residue  some  alcohol, 
let  it  settle,  and  operate  as  in  the  fi.rst  case.  The  residue  is 
then  placed  upon  a  filter  and  completely  washed  out  with 
alcohol.  The  residue  left  on  the  filter  consists  principally 
of  carbonate  and  sulphate  of  alkalies,  carbonate  of  lime,  and 
other  mechanical  admixtures.  The  residue  is  dissolved  on 
the  filter  and  with  distilled  water,  washed  out,  when  test 
the  carbonate  of  alkali  in  the  filtration,  by  alkalimetry,  as 
also  the  sulphuric  acid  present,  by  chloride  of  barium  in  the 
liquid  soured  with  muriatic  acid.  The  sulphate  of  barium 
is  placed  upon  a  filter,  washed  out  with  distilled  water, 
dried,  calcined,  and  weighed.  We  calculate  thus  the  sul- 
phuric acid  present,  respectively,  in  the  sulphate  of  potash  and 
the  sulphate  of  soda:  116.5  parts  sulphate  of  barium  corre- 
spond to  40  parts  of  anhydrous  sulphuric  acid,  87.11  parts 
anhydrous  sulphate  of  potash  and  71  parts  anhydrous  sul- 
phate of  soda.  The  liquid  filtered  oflT  from  the  sulphate  of 
barium  is  mixed  for  assaying  the  surplus  addition  of  barium 
first  with  ammonia,  then  w^ith  carbonate  of  ammonia,  filtered 
and  washed  out.  The  filtered  liquid  is  eva])orated  in  a  small 
porcelain  saucer  until  dry,  and  the  muriate  of  ammonia 
ejected  by  calcination.  The  saucer  is  now  placed  upon  a 
sensitive  scale  and  balanced,  emptying  its  co?itents  without 


SOAP  ANALYSIS. 


353 


loss  into  a  100  cubic  centimetre  (3.38  fl.  ozs.)  measuring  flask, 
rinsing  the  saucer  with  water, drying  it  by  warming, placing  it 
again  upon  the  scale,  and  b}^  additional  weights  causing  it  to 
balance.  The  weights  placed  on  after  deducting  the  calculated 
sulphate  of  potash  found  in  the  sulphuric  acid,  show  the  alka- 
lies present  as  chloride  of  potassium  and  chloride  of  sodium. 
We  will  designate  this  weight  by  A.  To  find  herefrom  the 
respective  quantities  of  soda  and  potash,  we  determine  the 
quantity  of  chloride  in  A,  by  dissolving  the  salt  mixture  to 
lOO  cubic  centimetres  (3.38  fl.  ozs.),  then  placing  a  certain 
part  of  this  solution  (10  to  20  cubic  centimetres  =  0.338  to 
0.676  fl.  oz.)  in  a  white  porcelain  saucer,  adding  a  few  drops 
of  neutral  chromate  of  potassa,  and  then  from  a  -^-q  cubic 
centimetre  graduated  pipette  so  much  standard  nitrate  of 
silver  solution  until  the  ensuing  precipitate  shows  a  reddish 
coloring.  By  determining,  the  chloride,  the  data  for  con- 
tinuing the  calculation  are  given.  We  know  now,  1,  the 
weight  A,  and,  2,  that  of  the  chloride  contained  therein  = 
C.  If  the  two  unknown  quantities  are  designated  chloride 
of  potassa  with  x  and  chloride  of  sodium  with  y,  there  is 
X  +  y  =  A.  I. 
The  chloride  of  potassa  contains  the  0.47552  of  its  weight 
of  chloride,  the  chloride  of  sodium  the  0.60657  part  of  its 
weight  of  chloride. 

X  parts  chloride  of  potassa  hence  0.47552  x  parts  chloride  and 
X  parts  chloride  of  sodium  hence  0.60657  y    "  " 
0.47552  X  +  0.60657  y  =  II. 
If  we  place  of  equation  I.  for  x  its  value,  to  wit,  x  =  A 
—  y,  and  substitute  it  in  the  equation  II.,  then  we  obtain : 
0.47552  A  +  0.13105  y  =  C,  and  herefrom 

^  C  —  0.47552  A 
^  0.13105 
^  _  0.60657  A  — C 
0.13105 

From  the  figures  thus  found  for  the  chloride  of  potassa 
and  the  chloride  of  sodium,  we  calculate  the  potash  and  the 
soda  according  to  the  proportions. 
23 


354  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

74.56  parts  chloride  of  potassa  are  =  47.11  parts  potash  and 
58.45    "     chloride  of  sodium       =  31.00    "  soda. 

These  salts  do  not  form  a  constituting  ingredient  of  the 
soap,  they  are  an  intentional  or  accidental  surplus  present. 
The  sulphuric  acid  is,  in  the  first  place,  calculated  as  sulphate 
of  potassium  and  a  surplus  as  sulphate  of  sodium,  the  rest 
is  carbonate  of  potassa  or  carbonate  of  soda.  The  alkaline 
chloride,  and  also  the  free  caustic  alkalies,  are  found  in  the 
alcoholic  solution,  and  are  determined  in  the  following  man- 
ner: This  alcoholic  solution  is  well  and  constantly  shaken, 
with  an  accurately  weighed  quantity  of  bicarbonate  of 
soda,  or  potash.  By  this  process  the  caustic  alkalies  change 
into  carbonates,  which,  as  they  are  insoluble  in  alcohol,  will 
precipitate  to  the  bottom,  l^ow  we  decant,  rinse  the  resi- 
due with  alcohol,  and  then  place  upon  a  filter,  where  it  is 
fully  washed  out  with  alcohol.  The  residue  upon  the  filter, 
dissolved  in  distilled  water,  determines  in  the  filtrations 
by  means  of  standard  nitric  acid  the  carbonate  of  soda,  and 
deducting  from  the  quantity  thus  found,  the  applied  bicar- 
bonate of  soda,  the  rest  is  that  surplus  carbonate  of  sodium, 
which  was  present  in  tlie  soap. 

In  the  alcoholic  soap  solution  now  only  remains  for  deter- 
mination the  chloride  of  potassa,  as  also  the  alkalies  com- 
bined with  the  sebacic  acids.  For  this  purpose,  the  solution 
is  divided  into  two  equal  parts.  The  one  of  these  parts  is 
analyzed  by  a  measured  quantity  of  standard  nitric  acid, 
which  is  warmed  until  the  separated  sebacic  acid  melts, 
separating  them,  after  they  congeal,  melting  them  again  in 
distilled  water,  and  uniting  the  here  obtained  acidy  liquids. 
The  surplus  of  the  acid  is  now  titrated  back,  and  finding 
now  from  the  nitric  acid  neutralized  by  the  alkalies,  the 
alkalies  present  potash  and  soda.  In  the  same  liquid,  after 
having  been  made  somewhat  alkaline  by  a  few  drops  of  car- 
bonate of  soda ;  and  having  colored  it  yellow,  with  neutral 
chromate  of  potassa,  we  determine  by  means  of  j-q  nitrate  of 
silver,  the  value  of  chloride  of  potash. 

A  more  simple,  although  less  accurate,  yet  in  most  cases 
amply  sufficient  method,  by  which  to  determine  the  value  of 


SOAP  ANALYSIS. 


355 


free  alkalies  (caustic  as  well  as  carbonate)  contained  in  soaps, 
consists  in  weighing  a  portion  of  the  soap,  dissolving  the 
same  in  distilled  water,  and  separating  it  with  culinary  salt, 
which  has  no  earthy  salts,  gypsum,  chloride  of  calcium,  or 
chloride  of  magnesium,  etc.,  or  rock-salt.  We  must  not  warm 
it,  so  that  the  soap  separates  grainy,  and  it  is  then  washed 
out  upon  a  filter  with  a  concentrated  solution  of  pure  chloride 
of  sodium.  In  the  filtered  liquid^  the  alkalies  are  found 
dissolved.  In  order  to  determine  the  carbonate  and  the 
caustic  alkali  separately,  the  solution  is  mixed  with  chloride 
of  barium,  gathering  the  precipitate  upon  a  filter,  washing 
it  out,  and  putting  it  into  a  beaker  glass,  wherein  it  is  dis- 
solved in  a  surplus  of  measured  standard  nitric  acid,  and  the 
surplus  of  the  latter  is  then  analyzed  by  means  of  the  standard 
alkali.  From  the  nitric  acid  used,  the  quantity  of  carbonate 
of  potash  or  soda,  or  both  together  (specifically  only  the 
quantity  of  the  carbonates)  is  ascertained.  The  liquid  filtered 
ofl:*  from  the  carbonate  of  barium,  contains  the  caustic  alka- 
lies, which  may  then  be  determined  by  alkalimetry.  In  the 
testing  of  soda-soaps,  as  a  rule  no  consideration  need  be  taken 
as  to  their  value  in  potash ;  but  if  this  is  nevertheless  in- 
tended, one  part  of  the  liquid  is  to  be  concentrated  and  mixed 
with  bichloride  of  platinum.  If  no  yellow  precipitate  ensues 
then  no  potash  is  present. 

It  yet  remains  to  determine  the  relative  quantities  of  pot- 
ash and  soda,  which  have  really  formed  the  soap.  To  this 
end,  the  other  part  of  the  alcoholic  soap  solution  is  to  be 
analyzed.  This  is  done  by  muriatic  acid,  separating  the 
sebacic  acid  from  the  liquids,  washing  it  well  with  water, 
and  finally  evaporating  theacidy  lye  with  the  washing  water 
in  a  porcelain  saucer,  until  it  becomes  entirely  dry.  Here 
great  care  must  be  taken,  so  that  no  loss  is  experienced.  The 
porcelain  saucer,  while  yet  a  little  warm,  is  placed  on  the 
scale  and  balanced;  it  is  then  removed,  emptied,  rinsed,  and 
dried  by  warming,  and  again  placed  while  yet  a  little  warm 
upon  the  scale  and  again  ^weighed.  Thus  the  aggregate 
quantity  of  alkaline  chlorides  is  obtained,  from  which  the 
chloride  of  potassa  found  in  the  first  test  is  deducted,  and 


356 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


from  the  rest,  by  the  above  stated  process,  the  proportion 
between  the  potash  and  soda  is  calculated.  The  quantities 
thus  found  are  to  be  doubled  for  the  soap  which  is  tested 

We  have  yet  to  consider  the  residuum,  which  in  dissolving 
in  distilled  water  remains  upon  the  filter.  It  consists  of  car- 
bonate of  lime,  carbonate  of  dolomite,  clay,  and  silicic  acid. 
Its  quantity  is  as  a  rule  very  small,  and  the  determination 
of  these  substances  can  be  taken  simultaneously,  by  taking 
the  dried  precipitate  from  the  filter,  calcining  in  a  platina 
crucible  and  burning  the  filter,  and  weighing  the  whole. 

Another  method  for  determining  the  alkalies  combined 
with  the  sebacic  acids,  has  the  advantage  that  the  potash  is 
at  least  directly  determined,  and  consists  in  this:  The  alco- 
holic soap-solution  is  evaporated  by  the  volatilization  of  the 
alcohol,  diluting  with  water;  the  solution  is  decomposed 
by  oxalic  acid  to  a  weak  acidy  reaction,  the  sebacic  acids 
are  separated,  the  liquid  evaporated  to  dryness,  the  residue 
calcined,  and  the  coaled  mass  completely  washed  out  with 
distilled  water.  It  is  now  filtered,  the  coal  washed  out  and 
determined  in  the  filter,  the  value  of  the  alkali  by  titrating 
with  a  solution  of  tartaric  acid  (75  grammes  (2.63  ozs.)  to  1000 
cubic  centimetres  (1  litre  =  2.1  pints)  dissolved),  then  adding 
of  the  solution  of  tartaric  acid  again  as  much  as  had  been  used 
for  neutralization,  evaporating  the  liquid  in  the  water-bath 
until  dry,  cooling  to  the  temperature  of  the  room,  and  treating 
the  salt  residue  saturated  at  the  same  temperature  with  a  solu- 
tion of  bitartrate  of  potassa.  This  now  dissolves  the  foreign 
salts,  and  leaves  the  potash  as  bitartrate  of  potash,  which  is 
dried  by  a  gentle  heat,  and  then  weighed.  From  the  weight 
the  potash  contained  therein  is  calculated. 

100  parts  of  the  dried  bitartrate  of  potassa  correspond 
to  25.04  potash.  If  the  potash  thus  found  is  deducted  from 
the  aggregate  quantity  of  the  alkalies,  obtained  by  titration 
with  tartaric  acid,  then  the  rest  is  soda. 

By  the  chloride  of  platinum  also,  the  potash  can  be  di- 
rectly determined ;  this  method  is  however  rather  expensive. 
For  discerning  the  free  alkalies  in  soap.  Stein  has  proposed 
a  very  simple  method,  by  which  it  becomes  obvious,  without 


SOAP  ANALYSTS. 


357 


further  trouble,  whether  free  alkali  is  present  or  not.  Stein 
applies  to  this  end  corrosive  sublimate  (bichloride  of  mercury), 
which  furnishes  with  the  sebacic  acid  a  white  sebacic  peroxyd 
of  mercury  combination,  while  in  the  absence  of  a  free  alkali 
(caustic  as  well  as  carbonate)  red  peroxyd  of  mercury  is 
formed.  Stass  has  proposed  for  this  same  purpose  calomel, 
which,  if  free  alkali  be  present,  becomes  black.  The  subli- 
mate has  however  the  advantage  over  calomel,  that  it  can  be 
applied  in  solution,  and  also  that  soaps  may  be  tested  with 
it  without  dissolving  them,  by  moistening  a  fresh  cut  sur- 
face with  a  solution  of  sublimate.  On  the  other  hand,  for 
determining  the  free  alkalies  in  rosin  soaps,  binitrate  of 
mercury  is  well  adapted.  By  its  application  for  testing  rosin 
soaps,  the  heating  of  the  liquid  must  be  avoided,  because  by 
the  resinous  acid  protoxyd  of  mercury  may  suffer  a  decom- 
position. 

Determination  of  the  Amount  of  Sebacic  Acids  and  of  the 
Rosin. — For  this  operation  the  sebacic  acids  may  be  used,  as 
we  have  separated  them  by  the  two  preceding  methods. 
Especial  care  must  be  taken  that  no  loss  is  incurred,  which 
might  easily  happen,  because  the  sebacic  acid  will  adhere  to 
the  sides  of  the  vessels,  and  from  thence  cannot  be  again 
removed  by  water  and  be  regained.  This  is  attained  by 
washing  with  benzine,  which  by  heat  is  entirely  volatilized 
again.  If  by  this  means  all  sebacic  acid  has  become  re- 
united, the  sebacic  acids  are  melted,  thus  ejecting  the  ad- 
hering water  and  benzine.  But  these  acids  being  mostly  too 
soft  to  be  accurately  weighed,  they  are  usually  melted 
together,  with  dried  white  wax  or  stearic  acid,  which  sub- 
stances have  been  previously  accurately  weighed.  The  fat 
cake  is  placed  upon  a  filter,  and  washed  out  with  distilled 
water,  until  the  washing  water  is  no  longer  acid.  The  dry- 
ing is  performed  under  a  glass  cover  with  concentrated  sul- 
phuric acid.  The  drying  may  also  be  performed  in  a  porce- 
lain saucer  over  a  water  bath,  and  can  be  continued  as  Ions: 
as  the  saucer  no  longer  loses  in  weight,  whereupon  the 
melted  acid  is  poured  out,  the  saucer  cleansed  with  a  little  lye, 
dryed  off,  and  when  thus  empty  is  weighed.   From  the  aggre- 


358  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES, 


gate  weight  is  deducted  in  the  first  place  that  of  the  wax  or 
stearic  acid.  The  rest  represents  the  hydrates  of  sebacic 
acid,  in  case  rosin  soap  is  not  investigated.  The  hydrates 
of  stearic  acid,  palmitic  acid,  and  oleic  acid  have  nearly  the 
same  value  of  water,  which  with  sufficient  accuracy  may  be 
placed  at  3.25  per  cent.  From  the  weight  of  sebacic  acid 
found,  3.25  per  cent,  are  therefore  deducted  and  the  rest  as 
the  sebacic  acid  is  taken  into  the  analysis.  Very  frequently 
it  happens,  that  the  hydrate  of  the  sebacic  acids  is  not  de- 
ducted, and  the  hydrates  of  the  same  anhydrous  sebacic 
acids  calculated.  By  the  error  thus  committed,  the  value  of 
the  sebacic  acid  in  the  soap  appears  too  high. 

Under  certain  circumstances  the  melting  points  of  the 
various  acids  may  give  a  basis  as  to  the  kind  and  derivation 
of  the  sebacic  acids,  especially  if  the  point  in  question  is  to 
determine  whether  two  samples  of  soap  before  us  are  equal 
or  varying.  For  this  experiment  a  small  quantity  of  sebacic 
acid  is  melted  and  the  temperature  observed.  While  slowly 
cooling  olf,  the  mercury  in  the  thermometer  will  be  observed 
remaining  somewhat  longer  at  a  fixed  degree,  whenever  the 
point  of  congelation  is  reached,  and  the  temperature  thus 
indicated  is  the  melting  point.  If  but  little  of  the  sebacic 
acid  is  at  our  disposal,  then  according  to  Douis  we  operate 
as  follows:  A  thin  glass  tube  is  taken,  drawn  out  to  a  very 
narrow  tube,  and  the  narrower  part,  which  is  turned  down- 
ward, is  filled  up  with  the  melted  acid.  After  the  congeal- 
ing has  taken  place,  the  apparatus  is  placed  in  water,  which 
is  slowly  heated.  At  the  moment  of  melting,  the  partly 
melted  sebacic  acid  is  forced  upward  by  the  pressure  of  the 
water.  The  temperature  of  the  water,  at  which  this  obser- 
vation takes  place,  is  also  the  melting  point  of  the  acid. 

According  to  Stockhardt  the  sebacic  acids  congeal  as 
follows : — 

of  pure  tallow  soap  at  44o  to  450  C.  (111.20  to  113°  F.) 

of  pure  palm  oil  soap  at  38o  to  39o  C.  (100.4O  to  102.2O  F.) 

of  1  part  tallow  and  I  part  cocoa  oil  at  32©  to  350  C.  (  89.60  to  95^  F.) 
of  1  part  tallow  and  ^  "  "       at  290  to  30o  C.  (  84. 20  to  860  F.) 

of  1  part  tallow  and  1  "  "       at  27°  to  280  C.  (  80.60  to  82.40  F.) 

of  1  part  palm  and  ^     "  "       at  270  to  280  C.  (  80.6O  to  82.40  F.) 

of  pure  cocoa-nut  oil  at  23o  to  240  C.  (  73.4o  to  75.20  F.) 


SOAP  ANALYSIS. 


359 


A  less  accurate,  but  for  all  common  cases  amply  sufficient 
method  to  determine  the  value  of  sebacic  acid  in  a  soap,  when 
the  separated  fat,  instead  of  being  weighed,  is  measured,  has 
been  proposed  by  Buchner.  To  this  end  is  used  an  alem- 
bic of  glass,  with  a  long  and  not  too  wide  neck  in  which  is 
inserted  a  scale  graduated  into  i  cubic  centimetres  (0.054  flui- 
drachm).  In  this  apparatus  are  placed  16 1  grammes  (0.58 
ounce)  soap,  with  diluted  muriatic  acid,  and  heated.  If  the 
decomposition  is  perfect,  lukewarm  water  is  used  to  fill  up, 
until  the  division  mark  between  the  watery  and  the  fatty 
layer  reaches  the  zero  point  of  the  scale,  or  is  somewhat 
above  it.  After  leaving  it  to  cool  off  to  the  temperature 
of  the  room,  the  height  of  the  fatty  layer  is  read.  If  the 
specific  gravity  of  sebacic  acid  is  calculated  at  0.93  and  multi- 
plied by  the  indicated  cubic  centimetres, we  obtain  the  weight 
of  the  hydrartes  of  the  sebacic  acid,  and  can  thereby  calculate 
the  quantity  of  fat  which  has  been  applied  in  the  fabrica- 
tion of  the  soap.  According  to  Buchner,  50  kilog.  (110  lbs.) 
fat  furnish  77J  kilog.  (170.5  lbs.)  of  the  fine  grain  soap, 
and  about  ^\  glycerine.  For  an  easy  mode  of  calculation, 
Buchner  furnishes  the  following  table : — 


The  sebacic  acid 
separated  from 
16f  g.  soap  mea- 
sures  in  cubic 
centimetres 

Specific  gravity  of 
the  oils  and  fats. 

The  separated  se- 
bacic acid  hence 
weighs  in  the 
mean  in  grammes. 

The  fat  used  for 
100  l<:ilog.  soap. 

The  grain  soap 
contained  iu  loo 
weight  parts  of 
soap. 

100  weight  parts 
soap  contaia  of 
waier,  lye,  and 
glycerine. 

100  weight  parts 
soap  contain  of 
real  grain  soap. 

1 

0.93 

0.46 

3.13 

4.85 

97 

3 

5 

( i 

4.65 

31.30 

48.50 

69 

31 

6 

a 

5.58 

37.56 

58.20 

63 

37 

7 

i  i 

6.51 

43.82 

67.90 

57 

43 

8 

i  i 

7.44 

50.08 

77.60 

51 

49 

9 

I  i 

8.37 

56.34 

87.30 

44 

56 

10 

i  I 

9.30 

62.60 

97.00 

38 

62 

11 

10.23 

68.86 

106.7 

32 

68 

12 

a 

11.16 

75.12 

116.4 

26 

74 

13 

li 

12.09 

81.38 

126.1 

20 

80 

14 

1 1 

13.02 

84.64 

135.8 

13 

87 

15 

u 

13.95 

93.90 

145.5 

7 

93 

Determination  of  the  Amount  of  Rosin. — Pure  rosin  soaps  do 
not  generally  exist,  and  it  would  be  easy  if  such  were  the 


360  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


case  to  distinguish  the  rosin  soap  from  a  fat  soap.  On  the 
other  hand  the  determination  of  the  amount  of  rosin  in  a 
soap,  particularly  if  the  point  in  question  is  the  investiga- 
tion of  an  imitation,  is  very  often  of  great  importance,  in 
order  to  find  out  the  accurate  composition  of  such  a  soap,  to 
which  as  is  self-evident  the  determining:  of  the  amount  of 
rosin  contained  in  such  an  imitation  belongs.  There  are 
several  methods,  according  to  which  the  quantity  of  the 
rosin  contained  in  a  soap  can  be  determined.  Chemistry, 
however,  must  confess  that  it  has  not  yet  succeeded  in  find- 
ing a  ready  technical  method. 

The  following  method,  which  furnishes  reliable  results, 
originated  with  Sutherland.  According  to  this,  the  soap  is 
cut  up  into  small  pieces,  weighing  a  certain  quantity,  for 
instance  33J  grammes  (1.17  ozs.)  accurately,  and  pouring  over 
it,  in  a  porcelain  saucer,  some  strong  commercial  muriatic 
acid.  The  saucer  is  covered  with  a  glass  plate,  and  heated 
over  an  alcohol  flame  until  all  soap  pieces  are  perfectly  dis- 
solved and  decomposed,  and  the  sebacic  acid  with  the  rosin 
floats  above.  'Now  133i  to  166f  grammes  (4.67  to  5.83  ozs.) 
warm  water  are  added,  and  the  saucer  allowed  to  cool  off. 
The  now  congealed  fat-cake,  thereupon,  is  carefully  taken  oft\ 
and  can  be  already  judged  by  its  appearance,  whether  rosin 
is  contained  therein,  or  not.  It  is  remelted  with  warm  water, 
in  order  to  remove  all  adliering  acidy  solution,  and  again 
cooled  ofi*,  carefully  dried  with  blotting  paper,  and  melted 
again  without  water,  until  the  boiling  degree  is  reached. 
This  is  for  the  purpose  of  removing  the  last  vestige  of  water. 
After  cooling  oft',  the  fat-cake  is  placed  upon  the  scale,  to 
ascertain  its  exact  weight.  In  all  these  operations,  all  loss 
must  be  carefully  avoided. 

If  the  soap  were  a  pure  fat  soap,  the  fat  cake  thus  ob- 
tained, after  the  deduction  of  3.5  per  cent,  for  the  hydrate, 
would  be  95.5  per  cent,  of  the  originally  applied  fats,  and 
the  latter  can  be  easily  calculated.  But  if  rosin  be  present 
in  the  soap,  it  is  found  in  the  sebacic  acid  cake,  and  this 
must  now  be  treated  as  follows.  It  is  placed  in  a  porcelain 
saucer,  holding  about  J  kilog.  (1.1  lbs.)  water,  pouring  strong 


SOAP  ANALYSIS. 


361 


nitric  acid  over  it.  Then  it  is  heated  very  cautiously  until 
the  boiling  point  is  reached.  At  this  moment  a  violent  ebul- 
lition will  ensue,  and  thick  red  vapors  will  develop.  As  soon 
as  this  occurs,  the  lamp  is  immediately  removed  ;  and  is  placed 
under  it  again  when  the  violence  of  the  reaction  has  ceased. 
It  is  now  left  to  boil  a  few  minutes,  while  frequently  stirring 
with  a  glass  rod,  adding  now  and  then  small  portions  of  ni- 
tric acid,  until  no  more  red  vapors  develop.  All  these  ope- 
rations are  performed  in  the  open  air,  on  account  of  the  de- 
velopment of  acid  vapors.  It  is  again  cooled  off,  removing 
the  cake  of  sebacic  acid,  which  floats  upon  the  strong  acidy 
and  deei)ly  colored  acid  of  the  rosin,  washing  it  off,  and  re- 
melting  it  in  nitric  acid. 

After  cooling  oft*  it  is  finally  dried,  and  once  more  melted, 
by  itself  at  a  gentle  heat,  until  no  more  acid  vapors  appear, 
and  then  left  to  congeal.  What  remains  is  pure  sebacic 
acid,  and  the  difference  in  weight  (the  loss)  against  the 
weight  of  the  cake  first  weighed,  indicates  the  quantity  of 
the  rosin.  The  latter  is  thus  obtained  immediately,  but  the 
quantity  of  the  pure  sebacic  acids  found  must,  as  was  stated 
before,  be  calculated  after  the  reduction  of  the  neutral  fat. 
This  is  done  by  deducting  4J  per  cent.,  corresponding  to  the 
glycerine  present. 

If  the  soaps  have  been  made  with  oil,  i.  e.^  liquid  fats  or 
oleic  acid,  then  the  separated  sebacic  acids  do  not  congeal 
easily  into  a  solid  cake,  and  it  would  then  be  difficult  to 
weigh  them  accurately.  In  this  case  also  the  condition  of 
an  exactly  weighed  small  portion  of  white  dried  wax  serves 
to  melt  it  together,  in  order  to  obtain  a  firm  cake,  which  can 
be  weighed  without  trouble,  and  from  the  weight  of  this,  in 
order  to  ascertain  the  quantity  of  the  sebacic  acids,  the 
weight  of  the  added  wax  is  deducted. 

Of  this  mode  of  determination  we  have  to  remark,  that  too 
large  a  surplus  of  nitric  acid  must  be  avoided,  nor  should 
the  same  act  upon  the  sebacic  acid  cake  any  longer  than  is 
necessary,  since  according  to  Heintz,  a  small  portion  of  stearic 
acid  or  palmitic  acid  becomes  easily  oxydized. 


362  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Determination  of  Soap  as  to  Admixtures. — To  enhance  the 
weight  and  quantity  of  soaps,  they  are  frequently  mixed 
with  cheap,  grainy  bodies,  such  as  clay,  chalk,  silicic  acid, 
barytes,  starch,  etc.  These  substances  remain — by  treating 
the  soap  with  strong  alcohol — as  a  residuum,  and  may  then 
be,  as  to  their  nature,  further  investigated.  If  the  residue  is 
boiled  in  water,  and  a  thickish  liquid  is  produced,  which  can 
be  colored  dark-blue  by  one  or  a  few  drops  of  tincture  of 
iodine,  then  starch  is  present.  If  the  liquid  be  strongly  al- 
kaline, it  must,  before  adding  iodine  solution,  be  neutralized 
by  acetic  acid.  To  determine  whether  lime,  silicic  acid,  or 
clay  is  in  a  soap,  the  residue  is  treated  with  muriatic  acid, 
and  evaporated  over  a  water-bath  to  dryness.  If  silicic  acid 
be  present,  this  remains  as  a  grayish,  coarse  powder.  Clay 
is  present  in  the  liquid,  if  it  precipitates  with  ammonia  to  a 
glutinous  substance,  which  easily  dissolves  in  caustic  soda- 
lye  ;  and  if  chalk  be  present,  carbonate  of  lime  is  produced 
by  the  precipitate  obtained  of  the  filtered  liquid.  Oxalic  acid 
produces  a  white  precipitate  of  oxalate  of  lime. 

The  various  kinds  of  soap  have  often  been  treated  as  to 
their  compositions  or  combinations,  and  from  these  analyses 
is  learned  how  much  the  soaps  which  are  found  in  commerce 
difi'er  from  each  other.  We  annex  some  of  these  analyses 
below.  Moreover,  it  also  appears,  as  if  in  these  investiga- 
tions and  experiments  lime  and  dolomite  had  not  received  tljat 
attention  which  they  deserve  as  ingredients  of  a  soap;  since 
none  of  these  analyses  mention  these  minerals  as  ingredients 
of  soap.  And  yet  it  is  doubtful  if  there  exists  a  soap  in 
which  they  are  not  present.  And  in  such  a  case,  we  may 
surely  suppose,  that  they  are  present  as  sebacic  acid  salts, 
forming  a  portion  of  the  sebacic  acids. 


SOAP  ANALYSIS. 


363 


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364 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Valuation  of  Soaps. — The  value  of  soaps  is  determined  gen- 
erally, according  to  their  contents  of  neutral  fats  or  sebacic 
acids.  Although  soaps  with  a  certain  excess  of  free  or  car- 
bonated alkali  take  better  hold,  that  is,  act  stronger  for  the 
removal  of  dirt,  it  must  not  be  overlooked  that  the  free  alkali 
not  only  hurts  the  hands,  but  also  the  textile  fibres  of  the 
articles  washed.  For  this  reason,  since  soaps  seldom  are  in 
the  market  with  excess  of  fat,  the  sebacic  acid  value  of  a 
soap  may  be  considered  the  correct  rule  and  measure  for 
the  value  of  a  soap.  This  however  is  subject  to  a  limit, 
in  so  far,  as  the  equivalents  of  the  sebacic  acids  are  some- 
what varying,  so  that  equal  weights  of  various  sebacic  acids, 
require  various  weight  proportions  of  alkali,  in  order  to  be 
changed  into  neutral  sebacic  salts.  If  in  this  manner  the 
Grain  (curd)  and  Paste  (cold)  soaps  are  compared  with  each 
other,  they  correspond  (if  the  greatly  filled  soaps  are  ex- 
cepted), in  regard  to  their  value  of  neutral  sebacic  acid  soap, 
the  former  to  the  latter  approximately  as  15  :  11,  and  in  re- 
gard to  their  value  of  sebacic  acids  as  10  :  7.  In  commerce 
the  prices  of  grain  soaps  correspond  approximately  to  the  cold 
soaps,  =  7:6.  According  to  the  sebacic  acid — and  sebacic 
acid  soap  value,  the  prices  should  compare  as  8  :  6,  and  we 
find  hence,  that  the  cold  soaps,  in  comparison  with  the  grain 
(boiled)  soaps,  are  sold  too  high. 

If  despite  this  in  modern  times  the  use  of  cold  soaps  has 
overtaken  that  of  grain  soaps,  the  reason  of  this  is  partly 
found  in  the  fact,  that  the  cold  soaps,  by  dint  of  their  con- 
tents of  cocoa-nut  oil,  foam  very  much,  on  which  property 
a  certain  value  is  placed,  and  for  the  reason  that  it  is  really 
thought  they  are  cheaper ;  for  the  common  consumer,  who 
is  not  in  a  position  to  investigate  or  examine  a  soap  more 
accurately,  is  constrained  to  regard  such  external,  and  in 
this  case  deceptive  signs,  as  firmness  and  good  frothing  are. 
On  the  other  hand,  it  has  also  happened  that  wool-wash- 
ing establishments,  whose  demands  for  soap  amounted  to 
several  thousand  pounds  per  week,  very  soon  made  the  ob- 
servation, that  they  used  i  to  J  more  of  a  good  cold  soap  than 
of  an  equally  good  boiled  soap.    The  proportion  was  also 


SOAP  ANALYSIS. 


365 


here  more  unfavorable  than  was  stated  above,  or  perhaps 
for  the  reason  that  the  greater  solubility  of  the  cold  soap 
brought  with  it  a  larger  consumption. 

Cailletet's  Process. 

It  may  interest  the  manufacturer  to  read  the  details  of  this 
process,  which  we  give  in  full  from  the  Bulletin  de  la  Societe 
Industrielle  de  Mulhouse  (Eo.  144,  vol.  xxix.  p.  8). 

Characteristics  of  the  Aqueous  Solutions  of  Soaps ^  Normal 
Acid,  and  Alkaline  Liquor. — The  soaps  used  in  industry  are 
formed  of  fatty  acids,  of  soda  and  potash,  and  water.  These 
acids,  which  are  solid  or  liquid  at  the  ordinary  temperature, 
are  extracted  from  fatty  substances  of  animal  or  vegetable 
origin. 

The  soap  of  oleic  acid  often  contains  rosin. 
The  Avhite  soap  obtained  by  the  Marseilles  process  is 
formed  of : — 

60  to  64  parts  of  fatty  acids. 
80  to  36  ^vater. 
6      "  soda. 

Some  white  soaps  are  met  with  in  the  trade  which  contain 
from  40  to  50  per  cent,  of  water.  The  marbled  soap  cannot 
contain  more  than  thirty-four  per  cent. 

When  the  soap  separates  from  a  saturated  saline  solution, 
it  is  formed  of : — 

Fatty  acids  .......  77 

Soda   .7 

Water  16 

When  anhydrous  the  same  soap  contains: — 

Fatty  acids  .......  91 

Soda    ........  9 

In  certain  industries,  soaps  are  used  into  which  there  enters 
more  than  six  per  cent,  of  soda.  These  soaps  by  their  ex- 
cess of  alkali,  and  according  to  their  mode  of  fabrication, 
may  be  hydrated  enough  to  contain  from  50  to  60  per  cent, 
of  water. 


366 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


The  fatty  substances  which  enter  into  the  composition  of 
soaps  are  generally  oleic,  margaric,  stearic,  and  palmitic 
acids.  The  more  or  less  consistency  of  the  aqueous  solution 
of  a  soap  is  due  to  the  presence  of  solid  fatty  acids,  or  to  an 
excess  of  alkali. 

To  prepare  an  aqueous  solution  of  soap,  take  ten  grammes 
of  the  soap  to  be  tested,  introduce  it  into  a  wide-mouthed 
bottle  and  add  90  grammes  (3.15  ozs.)  of  cold  distilled  water, 
and  dissolve  over  a  water-bath.  Introduce  this  solution  into 
a  test  tube  of  a  capacity  of  100  cubic  centimetres  (3.38  fl. 
ozs.),  and  one  hour  after,  examine  its  consistency. 

Hard  soaps  generally  give  a  solution  which  by  cooling 
forms  an  opalescent  mass,  in  which  crystallizations  are  often 
seen  after  it  has  been  prepared  for  some  time.  Diluted  with 
cold  water,  this  solution  divides  into  an  acid  salt  which  de- 
posits, and  an  alkaline  salt  which  remains  in  solution.  The 
acid  salt  sometimes  deposits  in  the  form  of  a  flaky  substance, 
without  consistency ;  it  is  ordinarily  richer  in  solid  acids 
than  in  liquid;  sometimes,  as  with  a  solution  of  soap  of 
cocoa-nut  oil  diluted  with  its  volume  of  water,  the  acid  salt 
which  deposits  assumes  a  crystalline  form,  and  remains  at- 
tached to  the  edges  of  the  vessel  in  which  the  mixture  has 
-been  kept. 

A  warm  solution  of  10  grammes  (.35  oz.)  of  soap  of  olive  oil, 
and  90  grammes  (3.15  ozs.)  of  distilled  water,  is  transparent 
as  long  as  the  solution  is  warm,  but  as  soon  as  it  cools  down 
it  becomes  more  and  more  opalescent,  and  lastly,  when  cold, 
it  is  entirely  opaque.  Its  consistency  has  some  anology  with 
that  of  the  white  of  egg ;  it  can  be  drawn  in  threads,  and 
a  few  days  after  preparation  it  has  lost  some  of  its  con- 
sistency. If  in  the  soap  which  has  been  dissolved,  there 
have  entered  fatty  acids  due  to  a  mixture  of  sesame  and 
olive  oils,  olive  oil  and  earth-nut  oil,  etc.,  the  solution  is  less 
opaque  and  has  not  so  much  consistency  as  that  produced 
with  olive-oil  soap  alone.  If  in  the  composition  of  this  lat- 
ter there  enters  cocoa-nut  oil,  the  solution  is  partly  curded. 
A  solution  of  soap  of  cocoa-nut  oil  diluted  with  its  volume 


SOAP  ANALYSIS. 


367 


of  water  produces,  after  a  rest  of  twelve  hours,  an  abundant 
and  crystalline  precipitate  ;  the  liquor  is  colorless. 

Generally,  a  solution  made  with  10  grammes  (0.3-^  oz.)  of 
soap  and  90  grammes  (3.15  ozs.)  of  distilled  water  gives,  by 
cooling,  a  solution  much  more  opalescent  and  with  more 
consistency,  when  it  contains  more  solid  acids  and  alkali. 

Soaps  manufactured  with  solid  fatty  acids  give  a  solution 
which  is  solid.  Thus  3  grammes  (46.29  grains)  of  soap  of 
tallow,  and  97  grammes  (3.39  ounces)  of  water,  produce  a 
solid  solution. 

Soaps  in  which  liquid  fatty  acids  predominate  give  gener- 
ally a  colorless  solution  at  a  temperature  of  85°  to  100°  C. 
(185°  to  212°  F.).  When  the  fatty  acids  predominate,  as  in 
the  tallow  soap,  the  solution  looks  flocculent.  If  the  soap 
contains  rosin,  the  solution  at  185°  to  212°  F.  is  very  opaque, 
and  after  being  prepared  a  few  hours  it  separates  into  three 
parts.  The  upper  part,  which  is  nearly  transparent,  con- 
tains very  little  rosin  and  much  alkali ;  the  middle  part  is 
entirely  opaque ;  the  lower  part  is  formed  with  a  white  sub- 
stance which  has  deposited  and  which  looks  like  pure  rosin 
combined  with  very  little  alkali. 

All  soaps  are  heavier  than  water ;  they  do  not  act  in  the 
same  manner  when  in  contact  with,  warm  water.  If  a  piece  of 
soap  weighing  10  grammes  (0.35  oz.)  is  introduced  into  a  wide- 
mouthed  bottle  containing  90  grammes  (3.15  ounces)  of  cold 
distilled  water,  and  if  the  whole  is  heated  over  a  water-bath, 
the  soaps  manufactured  with  olive  oil,  palm  oil,  tallow,  oleic 
acid,  etc.,  will  float  on  the  surface  and  become  transparent 
from  the  circumference  to  the  centre  ;  soon  by  their  contact 
with  -warm  water,  their  transparency  is  complete.  The 
contrary  takes  place,  if  the  soaps  have  been  manufactured 
with  cocoa-nut  oil  or  rosin  ;  they  remain  at  the  bottom  of 
the  vessel  and  dissolve  very  easily. 

The  soaps  of  olive  oil,  tallow,  etc.,  retain  their  transpa- 
rency all  the  w^hile  they  are  in  contact  wnth  warm  water. 
If  this  transparent  soap  is  taken  from  the  warm  water,  it 
will  retain  its  transparency  for  some  time;  but  if  the  soap 
is  half  out  of  the  water  and  is  allowed  to  cool,  the  part  in 


368 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


contact  with  the  liquid  becomes  white  and  opalescent,  while 
the  other  remains  transparent. 

Soap  in  contact  with  warm  water  loses  at  first  a  part  of 
alkali,  water,  and  fatty  substance ;  it  becomes  richer  in 
solid  acids  and  is  less  aqueous.  Its  transparency  is  as  much 
greater  as  it  contains  less  water  and  alkali ;  afterwards  its 
solution  in  warm  water  will  be  slower  if  it  contains  more 
stearic  than  margaric  acid,  and  more  of  this  latter  than 
oleic  acid.  Lastly,  each  kind  of  soap  by  its  solubility  in 
warm  water,  by  the  transparency  and  consistency  of  its 
aqueous  solution,  presents  to  the  observer  shades  more  easily 
seen  by  the  aid  of  a  comparative  examination. 

After  studying  the  characteristics  of  the  aqueous  solu- 
tion of  a  soap,  it  is  very  easy  to  determine  its  composition 
by  the  following  method :  This  process,  which  consists  in 
measuring  the  constituent  principles  of  a  soap  to  ascertain 
its  weight,  is  called  saponimetry^  by  which  the  manufacturer 
may,  in  half  an  hour,  test  several  specimens  of  soap,  com- 
pare them,  and  select  the  best  for  his  use. 

To  operate  according  to  this  method,  it  is  necessary  to 
prepare  beforehand  two  liquors,  one  which  is  acid,  the  other 
alkaline.  These  two  liquors  ought  to  be  kept  in  ground- 
stoppered  bottles. 

Preparation  of  the  Normal  Acid  Liquor, 

Take 

Monoliydrated  sulphuric  acid  (660)  .    .    189.84  grammes  (6.64  ozs.). 
Distilled  water  same  quantity. 

and  add,  after  the  cooling  of  the  liquor,  enough  water  to 
make  one  litre  (2.1  pints)  at  the  temperature  of  15°  C.(59°  F.). 

10  cubic  centimetres  (0.338  fluidounce)  of  normal  acid 
contain  1.8984  grammes  (29.29  grains)  of  monohydrated  sul- 
phuric acid,  and  are  equivalent,  in  forming  a  neutral  salt, 
to  1.2  grammes  (18.5  grains)  of  soda,  or  1.825  grammes  (28.16 
grains)  of  potash. 

The  equivalent  of  monohydrated  sulphuric  acid  is  612.5 
(SO3,  500  +  HO,  112.5  =  612.5). 

The  equivalent  of  soda  is  387.17. 


SOAP  ANALYSIS. 


369 


The  weight  of  sulphuric  acid  necessary  to  form  a  neutral 
salt  with  soda  (1.2  grammes),  is  known  by 

NaO         SO.HO         NaO  SO3HO 
387.17     :     612.5    :  :     1.2  :    ==  1.8984 

The  weight  of  this  acid,  wliich  has  to  be  mixed  with  a 
sufficient  quantity  of  water  to  form  one  litre  (2.1  pints)  of 
acid  liquor,  is  known  by 

1.8984  grm.xlOOO  c  c.  ^  _  grammes  (6.64  ozs.). 

10  c.  c. 

To  prepare  50  cubic  centimetres  of  acid  liquor,  we  have 

1.8984  grm.  X50  c.  c.  493  grammes  (0.33  oz.). 

10  c.  c. 

Preparation  of  the  Normal  Alkaline  Liquor. 

Pure  and  dry  carbonate  of  soda  .    .    41.016  grammes  (1.44  ozs.). 
Distilled  water  enough  to 

dissolve  the  carbonate  and  obtain  one  litre  of  alkaline  liquor 
at  a  temparature  of  15°  C.  (59°  F.). 

50  cubic  centimetres  (1.69  fluidounces)  of  this  liquor  ought 
to  contain  1.2  grammes  (18.5  grains)  of  soda,  a  weight  rep- 
resented by  2.0523  grammes  (31.66  grains)  of  carbonate  of 
soda. 

To  ascertain  the  weight  of  the  dry  carbonate  of  soda  which 
ought  to  represent  1.2  grammes  of  soda  to  saturate  1.8984 
grammes  (29.3  grains)  of  monohydrated  sulphuric  acid  con- 
tained in  10  cubic  centimetres  (0.33  fluidounces)  of  the  normal 
acid,  knowing  that  612.5  of  monohydrated  acid  saturates 
662.18  of  carbonate  of  soda  (NaO  387.17-1-002  275  =  662.17), 
we  have 

SO.IIO      NaO,  CO,         SO3HO  NaOCO^ 
612.5     :     662.17     :  :     1.8984    :       a;  =  2.0523 

We  find  2.0523  grammes  of  carbonate  of  soda  without 
water,  represeiiting  1.2  grammes  of  soda  which,  dissolved  in 
a  sufficient  quantity  of  water,  ought  to  give  50  cubic  centi- 
metres of  alkaline  liquor  at  a  temperature  of  15°  C.  (59°  F.). 

The  weight  of  carbonate  to  dissolve  in  a  sufficient  quantity 

24 


370  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


of  distilled  water  to  obtain  one  litre  of  alkaline  liquor  is 
known  by 

2.0523  grms.  XIOOO  c.  c.  _  ^  _  ^^^^^   ^^^^^^  44 
50  c.  c. 

These  normal  liquids  are  used  in — 


Saponimetry. 

Soaps  Composed  of  Solid  and  Liquid  Fatty  Acids. — The 
normal  acid  and  the  alkaline  liquor  being  prepared,  the 
question  is  to  determine  with  rapidity  the  weight  of  the 
fatty  matter,  the  alkali,  and  the  water,  without  being  obliged 
to  use  the  balance. 

To  obtain  this  result,  take  a  graduated  glass  tube  of  a 
capacity  of  50  cubic  centimetres  (1.69  fluidounces)  divided 
into  100  parts  (alkalimetry),  to  which  a  cork  is  adapted. 
Introduce  into  it  10  cubic  centimetres  (0.33  fluidounce)  of 
normal  acid.  This  acid  must  be  carefully  measured.  After- 
wards, add  to  it  20  cubic  centimetres  (0.66  fluidounce)  of 
spirit  of  turpentine  carefully  measured ;  then  weigh  10 
grammes  (0.35  ounce)  of  soap  divided  into  very  thin  shav- 
ings which  is  introduced  into  the  tube  ;  cork  the  tube;  stir 
for  a  few  minutes  until  the  soap  is  dissolved  and  then  let  it 
rest.  A  quarter  of  an  hour  is  suflicient  to  have  a  complete 
separation  of  the  turpentine,  of  the  dissolved  fatty  matter, 
and  of  the  water.*  The  heaviest  part,  which  is  water,  sul- 
phate of  soda,  and  sulphuric  acid,  falls  rapidly  to  the  bot- 
tom of  the  tube ;  the  lightest  part  formed  with  turpentine 
and  fatty  matter  occupies  the  upper  part ;  lastly,  a  layer 
formed  of  an  albuminous  or  animal  matter  occupies  the 
middle.  This  latter  layer,  which  is  neither  fatty  matter  nor 
water,  is  sometimes  voluminous  enough  to  occupy  the  whole 
of  the  capacity  of  the  tube  containing  the  normal  acid.  A 
slight  agitation  is  suflicient  to  collect  it  into  a  very  thin 

*  The  solution  of  the  fatty  matter  in  the  turpentine  takes  place  without 
dilatation  or  contraction  of  the  volume  ;  it  is  the  same  for  the  mixture  of 
the  normal  acid  with  the  water. 


SOAP  ANALYSIS. 


371 


layer.  In  this  state  it  is  between  the  normal  acid  and  the 
turpentine.  When  the  soap  contains  rosin,  this  substance 
partly  separates  from  the  fatty  matter,  and  forms  a  layer 
between  the  turpentine  and  the  acid,  but  it  preserves  its 
volume  whatever  is  done  to  unite  it  into  a  smaller  space. 

The  volume  of  the  turpentine  with  the  fatty  substance 
must  be  diminished  by  about  J  a  division,  or  J  of  a  cubic 
centimetre  (O.Od  fluidrachm),  and  the  volume  of  the  water 
ought  to  be  increased  by  that  diminution.  This  correction 
must  be  made,  because  the  water  attaches  itself  to  the  edges 
of  the  tube  and  diminishes  its  diameter,  which  causes  the 
lightest  volume  to  be  increased  a  little,  and  the  heaviest  to 
be  diminished. 

If  soap  made  with  olive  oil  is  tried,  the  total  volume  is 
about  79.5  divisions ;  if  the  trial  is  made  with  oleic  acid 
soap,  the  total  volume  is  from  80  to  81 ;  if  the  soap  is  made 
with  greases  or  heavy  oils,  the  volume  is  below  79.5  divi- 
sions. These  volumes  are  very  variable,  because  the  soaps 
may  contain  more  or  less  water,  and  the  fatty  substances 
may  have  a  greater  or  less  weight. 

Let  us  suppose  that  by  the  trial  of  a  white  soap  from  olive 
oil  the  volume  was  79.5  divisions,  and  the  volume  of  the 
normal  acid  and  water  contained  in  the  10  grammes  of  the 
soap  was  26  divisions,  we  have: — 

Total  volume       ...       .       .  79.5  di v. 
Less  the  vohtme  of  acid  and  water  26.0 
For  the  correction       .       .  .0.5 

Which  gives  53.0 

Less  the  volume  of  turpentine     .  40.0 

Balance      .      .      .  •^_13  c.  c.  =  6.5  c.  c.  (1.75  fldrm.). 

2 

As  there  has  been  used  10  cubic  centimetres  =  20  divi- 
sions of  normal  acid  according  to  the  composition  of  the 
soap,  the  volume  of  the  acid  water  is  26.5  divisions,  we 
have: — 

26  5  r  p 

—^-^  =  13.25  c.  c.  — 10  c.  c.  =  3.25  c.  c.  (0.88  fluidrachm). 


372 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Which  make: — 

Fatty  matter     ....    6.50  c.  c. 
Water  and  soda        .       ,       .  3.25 

9.75  "  (2.63  flmdrachms). 

The  soap  being  heavier  than  water,  the  volume  9.75  cubic 
centimetres  in  soap  represents  the  weight  of  10  cubic  centi- 
metres (2.70  fluidraclims)  of  water. 

To  know  the  weight  of  the  cubic  centimetre  of  the  fatty 
matter  contained  in  various  soaps,  Ave  remember  that  there 
have  been  introduced  into  the  tube  10  cubic  centimetres  of 
normal  acid,  20  cubic  centimetres  (0.66  fluidoz.)  spirit  of 
turpentine,  and  10  grammes  of  soap.  After  the  decomposi- 
tion of  the  soap,  the  height  of  the  total  volume  of  the  spirit, 
fatty  matter,  and  acid  water,  being  exactly  taken,  has  been 
of  79.5  divisions,  the  volume  of  the  aqueous  part  being  26 
divisions.  By  making  the  correction  spoken  of  before,  10 
grammes  of  the  soap  contain  in  volume: — 

Fatty  matter  6.50  c.  c.  >  9  75  c  c 

Water  and  soda      .       .       .       .    3.25  c.  c.  > 

On  the  other  hand,  the  author  has  dissolved  in  a  porcelain 
dish  10  grammes  (0.35  oz.)  of  the  same  soap  in  a  sufficient 
quantity  of  water,  to  which,  afterwards,  was  added  a  suffi- 
cient quantity  of  the  normal  sulphuric  acid  ;  after  the  sepa- 
ration of  the  fatty  acids  10  grammes  (0.35  oz.)  of  dried  white 
wax  were  added,  which  after  fusion  became  incorporated 
with  the  fatty  substance ;  and  after  cooling  the  cake  was 
dried  and  weighed.  The  total  weight  was  15.97  grammes 
(0.56  oz.).  From  this  weight,  if  we  subtract  that  of  the  wax, 
vrhich  is  10  grammes  (0.35  oz.),  the  balance  5.97  grammes 
(0.21  oz.)  represents  the  volume  6.5  cubic  centimetres  (1.75 
liuidrachms)  found  by  the  turpentine.  To  ascertain  the 
weight  of  a  cubic  centimetre  of  the  fatty  matter  contained 
in  Marseilles  soap,  we  have: — 

X  =  0.91846  gramme  (14.17  grains). 

6.5  c.  c. 

The  weight  of  the  cubic  centimetre  of  the  fatty  matter 
contained  in  several  specimens  of  Marseilles  soap  made  by 


SOAP  ANALYSIS. 


373 


different  manufacturers  was  0.91846,  0.91875,  0.91921 ;  the 
average  of  which  is  0.91880  gramme. 

The  weight  of  the  cubic  centimetre  of  fatty  substances 
from  cocoa-oil  soap  is  0.940  gramme. 

From  palm-oil  soap  0.922. 

From  tallow  soap  0.9714. 

From  oleic-acid  soap  0.9008. 

The  weight  of  the  fatty  matter  being  known,  we  have  to 
analyze  the  soda  and  water. 

Add  to  the  tube  which  contains  the  mixture  a  sufficient 
quantity  of  distilled  water  to  raise  the  level  of  the  turpen- 
tine ;  this  substance  and  the  fatty  matter  are  removed,  the 
tube  is  corked  and  well  stirred  to  dissolve  the  acid  sulphate 
of  soda  which  may  have  crystallized,  and  the  acid  mixture 
is  poured  into  a  test  glass.  Pour  a  little  more  water  into 
the  tube  so  as  to  wash  well  the  last  portions  of  acidulated 
water,  and  add  it  to  the  first  acid  solution.  Put  into  this  so- 
lution a  few  drops  of  tincture  of  litmus,  and  in  the  graduated 
tube  introduce  50  cubic  centimetres  (1.69  fluidozs.)  of  the  alka- 
line liquor;  pour  little  by  little  a  sufficient  quantity  of  this 
liquor  into  the  glass  containing  the  acid,  mixing  the  whole 
with  a  glass  rod  until  the  litmus  passes  to  the  onion  peel 
color.  The  liquor  has  to  be  tried  from  time  to  time  with 
litmus  paper,  and  when  this  paper  does  not  turn  red,  the  ad- 
dition of  the  alkaline  liquor  is  stopped  and  its  volume 
measured. 

Let  us  suppose  that  the  -^q^  of  the  alkaline  volume  have 
been  necessary  to  saturate  the  acid. 

The  alkaline  liquor  contains  in  50  cubic  centimetres  (1.69 
fluidozs.)  1.2  grammes  (18.50  grains)  of  soda.  This  weight 
forms  a  neutral  salt  with  the  sulphuric  acid  contained  in  the 
10  cubic  centimetres  (0.33  fluidoz.)  of  normal  acid  used  to 
decompose  the  soap.  It  the  operator  has  only  used  the  j%%  of 
50  cubic  centimetres  of  alkaline  liquor,  it  is  evident  that  the 
soap  contains  the  of  1.2  grammes  (18.50  grains)  of  soda. 
Then  the  volume  of  the  alkaline  liquor  which  is  not  used 
contains  exactly  a  weight  of  soda  equal  to  that  which  is 
found  in  the  10  grammes  (154.3  grains)  of  the  soap. 


374  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


To  apply  this  process,  if  the  operator  has  used  the  of 
the  alkaline  volume  for  the  saturation  of  the  acid,  the  soap 
contains  the  l-^  grammes  (18.50  grains)  of  soda,  or 

0.84  gramme  (12.96  grains),  or  8.40  per  cent. ;  if  the  volume 
used  has  been  j%%  the  soap  contains  0.6  gramme  (9.26  grains) 
of  soda,  or  six  per  cent. 

If  the  analysis  of  a  soft  soap  has  to  be  made,  what  is  left 
of  the  alkaline  volume  not  used  will  represent  the  propor- 
tional equivalent  of  the  potash  contained  in  the  soap.  The 
equivalent  of  the  soda  being  1.2  grammes,  that  of  the  potash 
is  1.825  grammes  (28.16  grains).  If  the  volume  not  used 
is  yYo?  is  evident  that  the  soap  contains  in  the  10  grammes 
of  1.825  grammes  of  potash  ;  if  the  volume  not  used 
is  it  is  manifest  that  the  soap  contains  j%%  of  1.825,  or 
9.125  per  cent,  of  potash. 

The  weight  of  the  soda  or  potash  being  determined,  it 
has  to  be  subtracted  from  the  water. 

The  analysis  of  a  soap  giving  in  volume: — 


Fatty  matter  ....  6.50  c.  c.  (1.75  fluidrachm) 
Water  and  soda ....    3.25    "    (  .88        "  ) 

if  the  weight  of  the  soda  is  0.60  gramme,  we  have : — 

Fatty  substance  6.5  c.  c.  X  0.91846  grm.  ==  5.9699  grms.  (92.16  grains). 
Soda   0.6000    "      (  9.00     "  ). 


Water  found  by  difference      .       .       .    3.4301*"     (52.84     "  ). 

Soap   10.0000    "    (154.00     "  ). 

If  the  soap  contains  glycerine,  this  substance  remains  in 
solution  in  the  normal  acid  ;  if  it  contains  flour,  talc,  clay, 

*  If  we  take  10  c.  c.  of  distilled  water,  and  5  grammes  (77.15  grains)  of 
potash,  the  volume  of  the  solution  at  60o  is  11.75  c.  c.  (3.17  fluidrachms). 
Supposing  that  soda  gives  the  same  result  as  potash,  we  have  to  know  the 
volume  of  0.6  gramme  (9.24  grains)  of  soda: — 

KO  Vol.  NaO.  Vol. 

5  grms.     :    1.75  c.  c.  :  :    0.60    :    a?  =  0.21  c.  c. 

77.15  grs.    :    0.47  fluidrachms.    :  :    9.24    :    a;  =  0.056  fluidrachms. 
Which  gives  for  the  volume  of  the  water  :  — 

3.25  c.  c.  —  0.21c.  c.  =3.04  c.  c.  of  water. 

0.87  fluidrachm  — 0.05  fluidrachm  =  0.82  fluidrachm. 


SOAP  ANALYSIS. 


375 


all  these  substances  fall  immediately  to  the  bottom  of  the 
tube. 

Soap  of  Oleic  Acid  and  Rosin.— li  10  grammes  (154  grains) 
of  rosin  soap  are  treated  b}^  10  cubic  centimetres  (0.33  fluidoz.) 
of  normal  acid ;  and  20  cubic  centimetres  (0.66  fluidoz.)  of  spirit 
of  turpentine,  the  latter  hardly  dissolves  any  of  the  rosin.  If 
a  certain  quantity  of  Marseilles  soap,  for  example,  enters 
into  the  weight  of  10  grammes  of  rosin  soap,  all  the  fatty 
matter  of  the  Marseilles  soap  is  dissolved  by  the  turpentine, 
and  the  rosin  is  dissolved  only  in  the  proportion  of  about 
the  yYo"  of  a  cubic  centimetre  (0.045  fluid rachm) ;  it  forms  a 
voluminous  layer  below  the  turpentine. 

This  easy  separation  of  the  rosin  ought  to  be  attributed 
to  a  special  state  it  acquires  while  in  presence  of  the  water 
when  separated  from  its  combination  with  potash  or  soda 
by  sulphuric  acid. 

These  results  are  described  in  the  two  following  experi- 
ments : — 

First  Experiment — 10  grammes  (0.35  oz.)  of  olive  soap 
containing  very  little  water  have  given  for  the  volume  of 
the  fatty  matter  8.25  cubic  centimetres  (2.23  fluid rachms). 

Second  Experiment. — 8  grammes  (123  grains)  of  the  same 
soap  and  2  grammes  (31  grains)  of  rosin  soap  have  given  a 
volume  of  the  fatty  matter  and  dissolved  rosin  equal  to  6.75 
cubic  centimetres  (1.82  fluidrachms). 

To  know  the  volume  from  the  8  grammes  of  olive  soap, 
we  have : — 

lOgrms.  :  8.25  c.  c.  :  :  8  grms.  :  a;  =  Vol.  6.60  c.  c.  (1.78  fluidrachra). 

If  from  the  volume  of  6.75  cubic  centimetres  we  subtract 
volume  6.60,  the  balance  0.15  indicates  that  the  turpentine 
has  dissolved  only  the  yYo-  of  a  cubic  centimetre  of  rosin. 

In  some  woollen  cloth  manufactories,  they  use  a  soap  made 
with  oleic  acid  and  rosin.  Let  us  suppose  that  10  grammes 
of  this  soap  have  given  by  the  wax  process  a  weight  of  fatty 
matter  and  rosin  ==  6.45  grammes  (99.52  grains),  that  by 
the  treatment  with  the  turpentine  the  volume  of  fatty  mat- 
ter and  dissolved  rosin  =  6.25  cubic  centimetres  (1.7  flui- 


876  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


drachm),  and  that  in  saturating  the  normal  acid  the  volume 
of  alkaline  liquor  employed  was 

Subtract  from  the  volume  6.25  cubic  centimetres  the  vol- 
ume 0.16,  which  gives  for  the  oleic  acid  6.25 — 0.15  6.10 
cubic  centimetres  (1.65  fluidrachms),  we  have: — 

Oleic  acid  6.10  c.  c.  X  0.9003  grm.  =  5.49183  grms.  (84.74  grains). 

Bosin  by  difference  grms.  —  n.mSS)  —0.95817  "  (14.78  "  ). 
Soda  1.2  grms.  Xt%^o  0.81600     "     (12.59     "  ). 

Water  by  difference  2.73400     "     (42.21     "  ). 

Soap  of  oleic  acid  and  rosin  10.00000         (154.32     "  ). 

The  weight  of  the  w^ax  -will  give  that  of  the  fatty  matter 
and  rosin;  the  volume  x  cubic  centimetre  of  the  fatty  matter 
— the  volume  0.15  of  the  rosin  multiplied  by  0.9003  weight 
of  a  cubic  centimetre  of  oleic  acid  will  give  the  weight  of 
that  volume.  By  difference  the  weight  of  the  rosin  wmII  be 
known  ;  the  volume  of  the  alkaline  liquor  not  used,  will 
give  the  weight  of  the  soda  or  potash ;  lastly,  by  difference, 
the  weight  of  the  water  is  obtained. 

Mixtuj^es  of  Potash  and  Soda. — In  some  soaps  there  is  a 
mixture  of  potash  and  soda.  The  weight  of  each  alkali  is 
known  by  the  following  method. 

Burn  10  grammes  (0.35  oz.)  of  soap.  Weigh  the  ashes  and 
treat  them  by  boiling  distilled  water:  filter,  wash  the  filter 
with  a  little  warm  water,  and  add  the  washings  to  the  alka- 
line solution ;  then  burn  the  filter,  deduct  the  known  weight 
of  its  ash  from  the  total  weight  of  the  ashes,  and  by  ditter- 
ence  we  have  the  weight  of  the  potash  and  soda  mixed  in 
the  state  of  carbonates. 

Let  us  suppose  that  the  mixture  weighs  3  grammes  (46.29 
grains).  The  volume  of  normal  acid  necessary  to  saturate  8 
grammes  of  the  mixture  is  found  by  a  direct  experiment. 
Then  the  volume  of  normal  acid  necessary  to  saturate  3 
grammes  of  carbonate  of  potash  and  3  grammes  of  carbon- 
ate of  soda  is  found  by  calculation.  The  volume  of  normal 
acid  by  which  the  three  grammes  of  the  mixture  have  been 
saturated  will  be  intermediate  between  the  volumes  w^hich 
ought  to  saturate  3  grammes  of  carbonate  of  potash,  and  3 


SOAP  ANALYSIS. 


377 


grammes  of  carbonate  of  soda.  By  a  proportional  division, 
we  shall  have  fractions  of  potash  and  soda  to  compose  the 
w^eight  of  the  mixture  examined. 

Let  us  suppose  that  the  volume  of  normal  acid  used 
directly  for  the  saturation  of  the  3  grammes  of  the  mixture 
is  13  cubic  centimetres  (3.51  fluid rachms). 

The  volume  of  normal  acid  to  saturate  3  grammes  of  car- 
bonate of  potash  and  3  grammes  of  carbonate  of  soda  is 
to  be  ascertained  ;  knowing  that  10  cubic  centimetres  (0.33 
fluidoz.)  of  normal  acid  contain  1.8984  grammes  (29.29 
grains)  of  monohydrated  sulphuric  acid,  and  that  its  equiva- 
lent is  612.5. 

For  the  carbonate  of  soda,  we  have: — 

NaO,C02       S03,H0         NaCCO.,      SO,,  HO 
662.17      :     612.5      ::       3       :     a;  =  2.774  grms.  (42.80  grains). 

To  know  the  volume  of  normal  acid  which  contains  2.774 
grammes  of  monohydrated  acid,  we  have : — 

SOg.HO       Vol.  S03,H0  Vol. 

1.8984   :  10  c.  c.  :  :  2.774  grms.  :  a;  =  14.612  c.  c.  (3.94  fluidrachms). 

In  the  same  manner  we  ascertain  the  weight  of  monohy- 
drated acid  and  afterwards  the  volume  of  normal  acid  which 
contains  the  weight  of  monohydrated  acid  necessary  to  satu- 
rate 3  grammes  of  carbonate  of  potash.    We  have: — 

K0,C02  SO,,  HO  KO,CO,  S03,H0 

863.93  :       612.5       :  :       3  :  a;  =  2.126  grms.  (32.80  grains). 
S03,H0         Vol.  SOg.HO 

1.8984  grms.  :  10  c.  c.  :  :  2.126  grms.  :  a;  =  11.198  c.  c.  (3.02  fldrms.) 

of  normal  acid,  which  contains  2.126  grammes  of  monohy- 
drated acid. 

By  experiment  13  cubic  centimetres  (3.51  fluidrachms)  of 
normal  acid  have  been  employed  to  saturate  the  alkalies 
found  in  the  ashes  of  the  calcined  soap.  It  is  evident  that 
if  the  weight  of  alkali  found  in  the  ashes  is  formed  only  of 
carbonate  of  soda,  the  volume  used  should  be  14.612  cubic 
centimetres  (3.94  fluidrachms)  of  normal  acid;  if,  on  the  con- 
trary, the  3  grammes  are  only  formed  of  carbonate  of  potash, 
the  volume  used  should  be  11.198  cubic  centimetres  (3.02 


878  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


fluidrachms)  of  normal  acid.  But  as  the  volume  of  normal 
acid  used  has  been  13  cubic  centimetres,  this  volume  alone 
indicates  a  mixture  of  carbonate  of  potash  and  soda.  By  a 
proportional  division  we  have  the  weight  of  the  carbonate  of 
soda  proportional  to  a  fraction  of  the  volume  14.612  cubic 
centimetres  of  normal  acid;  we  have  also  the  weight  of  the 
carbonate  of  potash  proportional  to  a  fraction  of  the  volume 
11.198  cubic  centimetres  of  normal  acid. 
To  establish  this  division,  we  have : — 

1.  The  gain  that  the  volume  11.198  ought  to  make  to  give  vol- 
ume  13  cubic  centimetres  which  is  1.802  cubic  centimetres  (0.49 
Jiuidrachm). 

2.  The  loss  that  the  volume  14.612  cubic  centimetres  ought  to 
make  to  give  13  cubic  centimetres^  which  is  1.612  cubic  centime- 
tres {0A2>  Jiuidrachm). 

Which  gives: — 

....  ^'^^^\=.^AU{i!).^2m^v^chm). 
Loss      ....    1.612  > 

To  compose  the  volume  13  cubic  centimetres,  we  take: — 

1.  The  Af^f  of  the  volume  14.612  cubic  centimetres^  corre- 
sponding to  the  \      of  2>  grammes  of  carbonate  of  soda. 

2.  The  If II  of  the  volume  11.198  cid)ic  centimetres^  corre- 
sponding to  the  -gfll      3  grammes  of  carbonate  of  potash. 

We  obtain : — 

x=  carb,  of  soda  1.5834  grms.  corr.  to  soda  0.92.j8  grm.  corr.  to  vol.  of  acid      7.7126  c.  c. 
y       "       "  pot.  1.4165     "       "         pot.  0.9656    *'       "       "       "       "  5.2873 


a;  +  2/  =  mixture  2.9999     "    both  1.8914  for  volume  found  12.99J9 

(46.29  graias).  (29.18  grains).  (3.51  fldrm.) 

In  this  analysis,  the  followino;  method  due  to  Glav  Lussac 
cannot  be  well  used,  because  too  much  soap  would  have  to 
be  burned  so  as  to  operate  on  50  grammes  of  mixed  chlorides. 

Operate  as  follows : — 

Transform  the  two  carbonates  into  chlorides  and  calcine 
to  evaporate  the  excess  of  acid  ;  take  50  grammes  (1.75  ozs.) 
of  the  mixture  which  is  finely  powdered,  introduce  this 
mixture  into  a  bottle  weighing  185  grammes  (6.48  ozs.),  and 
containing  200  grammes  (7.00  ozs.)  of  water,  stir  with  a  glass 


SOAP  ANALYSIS. 


379 


rod,  and  observe  the  falling  of  the  temperature  produced  by 
the  solution  of  the  salt  in  water. 

The  chloride  of  potassium  produces  a  falling  of  temperature 
of  11.4°  C.  (20.6°  F.).  Common  salt  in  the  same  condition 
produces  a  falling  of  1.9°  C.  (3.4°  F.). 

If  we  suppose  that  the  thermometer  marking  15°  C.  (59°  F.) 
falls  by  the  effect  of  the  dissolution  of  the  saline  mixture  to 
10°  C.  (50°  F.),we  have  a  falling  of  5°  C.  (9°  F.). 

By  proportionally  dividing  11.4°  and  1.9°  to  give  5°  C,  we 
have:  1st,  a  fraction  of  11.4°  corresponding  to  a  fraction  of 
100  grammes  (3.52  ozs.)  of  chloride  of  potassium  ;  2d,  a  frac- 
tion of  1.9°  corresponding  to  a  fraction  of  100  grammes  of 
chloride  of  sodium.    Therefore: — 

1.  Gain      5    —1.90  =  3.10  )  ^ 

2.  Loss     11.4  —  5.00  =  6.40  ^ 

Which  gives : — 

1.  The  |ig  of  11.4°  corresponding  to  the  fig  o/lOO  grammes 
of  chloride  of  potassium. 

2.  The  f  to  o/  1.9°  corresponding  to  the  ||g  of  100  grarames 
of  chloride  of  sodium. 

The  results  are : — 

Chloride  of  potassium  32.63  corresp.  to  temp.  3.720  C,  6.70  F. 
Chloride  of  sodium     67.37       "       "  1.28  2.3 

Total    100.000  falling  of  temp.    5.00O  C,  9.0o  F. 

The  tests  for  determining  the  amounts  of  the  alkalies  of 
potash  and  soda  are  rather  intricate ;  we  have,  therefore,  given 
the  reader  the  choice  of  methods  by  giving  Caillette's  also. 


380 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


SECTIOiT  XYII. 

RE-MELTING  OF  SOAP. 

This  operation  to  the  inexpert  is  quite  difficult,  taking 
much  time  and  being  attended  with  some  loss,  but  at  the  same 
time  it  is  very  important.  In  the  manufacture  of  soap,  in 
cutting,  moulding,  pressing,  etc.,  a  great  deal  of  scrap  soap 
accumulates,  and  it  often  happens,  that,  in  the  making  of  the 
soap,  it  may  not  turn  out  to  suit,  it  may  be  discolored, 
may  not  be  neutral,  or  may  have  too  little  alkali ;  or,  from 
whatever  cause,  and  these  are  many,  the  soap  even  with  the 
best  of  care  will  not  be  salable  and  will  have  to  be  re-melted 
and  adjusted. 

To  re- melt  the  scraps  and  soap  there  are  several  means. 
The  simplest  is  where,  in  the  case  of  having  a  steam  jacket 
with  cover,  the  soap  is  stripped  or  made  into  shreds  and 
placed  in  the  kettle  with  a  limited  quantity  of  w^ater, 
covered  closely,  and  the  steam  turned  into  the  jacket,  this 
operation  taking  much  time  and  requiring  some  attention 
in  stirring,  etc. 

Again,  one  of  the  best  modes  of  re-melting  by  means  of 
boiling  and  re-adjusting  is  to  cut  up  the  soap  into  small 
pieces;  in  which  case  it  need  not  go  into  the  stripper.  Place 
it  in  the  boiler  with  a  suitable  quantity  of  weak  lye,  say,  of 
2°  or  3^  B.  (half  the  w^eight  of  the  soap),  and  with  a  gentle 
heat  gradually  bring  to  a  boil  until  all  the  pieces  are  dis- 
solved, and  a  jelly  like  mass  is  obtained.  Then  add  suffi- 
cient culinary  salt,  or  a  strong  solution  of  it,  to  separate  the 
soap — an  operation  frequently  described — boil  to  a  curd, 
turn  off  the  heat,  let  it  settle,  and  remove  the  sub-lye.  If 
then  the  soap  is  too  hard,  it  will  be  necessary  to  fit  it.  This 
is  done  by  adding  a  portion  of  water,  and  again  bringing  it 


RE-MELTING  OF  SOAP. 


381 


to  a  boil  that  it  may  again  form  into  a  gelatinous  state  and 
be  subjected  to  the  usual  tests,  so  frequently  described.  If 
finished  it  is  framed.  If  the  soap  was  not  good  before  this 
operation,  the  boiling  and  adjusting  will  have  improved  it, 
though  it  may  not  be  as  white  as  it  was  before.  If  it  was 
much  discolored,  the  process  of  separation  may  be  repeated 
several  times. 

Soaps  that  have  a  filling  with  water-glass,  sal-soda,  or 
whatever  substance  should  not  be  re-melted  by  the  boiling 
process,  as  all  the  filling  would  be  separated  and  lost.  To 
re-melt  such  soaps,  a  valuable  machine  has  been  invented 
by  Mr.  Whitaker,  and  is  made  by  Messrs.  Hersey  Bros.,  of 
South  Boston,  Mass.,  which  has  proved  very  successful. 


Fig.  62. 


The  Whitaker  Re-melter. 


The  following  is  a  description  of  the  above  machine: 
A,  wrought  iron  cylinder  with  dishing  bottom.  B,  coil  of 
continuous  steam  pipe.    C,  horizontal  scroll  pipe  connecting 


382 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


with  the  upright  pipe.  D,  wire  diaphragm  which  serves  to 
separate  the  soap.  E,  gate  for  discharging  soap.  F,  small 
pipe  for  admitting  direct  steam  through  perforations  into 
the  body  of  the  soap.  K,  inlet  pipe  and  valve  for  direct 
steam.  I,  inlet  pipe.  J,  discharge  valve  for  condensed 
steam.  H  H,  floor  of  building.  Gr,  spout  for  running  in 
the  cut  soap. 

Directions  for  Use. — Fill  the  re-melter  with  the  soap,  put  on 
the  cover,  close  the  bottom  slide,  and  let  on  the  open  steam, 
until  the  soap  begins  to  melt,  which  will  depend  upon  the 
dryness  of  the  soap.  When  sufficiently  melted  shut  off  the 
open  steam,  open  the  bottom  to  drain  off  the  condensed  steam. 
Then  let  on  the  steam  through  the  coils  and  put  the  frames 
in  place  to  catch  the  melted  soap.  When  in  the  frames  stir 
well  when  half-full  and  also  when  full,  in  order  to  insure 
a  uniform  soap. 

This  machine  will  hold  about  1000  pounds  of  soap,  and 
can  be  used  six  or  eight  times  a  day.  It  is  now  used  by 
many  of  our  largest  manufacturers  both  for  domestic  and 
for  toilet  soaps. 

The  re-melting  of  soaps  is  a  very  important  part  of  soap 
manipulation,  for  independent  of  the  scraps  and  faulty  soaps, 
this  re-melter  might  be  used  to  re-melt  the  stock  soaps  for 
toilet  soaps  described  in  that  section,  especially  if  they  should 
become  with  drying  too  hard  and  brittle  to  mill. 

It  may  be  unnecessary  to  say  that  with  proper  care  in  the 
first  operation  of  making  the  soaps  there  will  be  less  re-melt- 
ing to  be  done,  and  in  toilet  soaps  the  various  appliances  of 
stripper  mill  and  platter  generally  cause  a  thorough  blending 
of  color  and  scraps,  and  the  mixing  of  the  soap  is  attained 
much  more  speedily  and  with  less  expense. 


MISCELLANEOUS  USEFUL  SOAPS. 


383 


SECTIOIS'  XVIII. 

MISCELLANEOUS  USEFUL  SOAPS. 

Though  we  have  given  in  our  preceding  pages  the  most 
important  soaps  known  to  commerce,  there  are  many  that 
have  had  a  reputation  more  or  less  deserving  or  transient, 
that  should  receive  some  notice  at  our  hands,  and  there  are 
also  soaps  made  in  the  household  and  for  domestic  and 
laundry  purposes  that  have  some  merit  and  are  economical. 

Altenburge's  Eosin  Soap. 

Cocoa-nut  oil      ....    100  kilog.     (220  lbs.) 

Rosin  100  (220  "  ) 

Soda  lye,  280      .       .       .       .    135    "         (297  "  ) 

Make  by  the  cold  process,  and  before  framing  cut  with  a 
salt  lye  of  24°  B. 

Dresden  Palm  Soap. 

Cocoa-nut  oil  ....  1600  kilog.  (3520  lbs.) 
Palm  oil  (crude)  .       .       .       .500    "      (1100"  ) 

Rosin   400    "      (  880  "  ) 

Soda  lye,  280     ....    1304  litres  (  353  gals.) 

Melt  together  the  fats  and  saponify  the  rosin  separately, 
taking  care  to  add  the  rosin  soap  before  it  becomes  too  thick 
to  stir. 

Offenbach  Palm  Soap. 

Palm  oil  (unbleached) .  .  .  1000  kilog.  (2200  lbs.) 
Cocoa-nut  oil  .  .  .  .  400  "  (  880  "  ) 
Soda  lye  15o  B   2800    "      (6160  "  ) 

Place  one-half  the  lye  with  the  fats  and  let  it  boil  gently 
to  saponify  slowly ;  when  combined  add  the  last  of  the  alkali, 


384 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


keeping  up  the  boiling  until  it  becomes  a  jelly.  If  stringy, 
add  a  portion  of  20°  lye,  and  if  too  caustic  correct  with  oleic 
acid. 


This  is  simply  a  good  tallow  soap  or  a  mixed  tallow, 
bleached  palm  oil,  or  cocoa-nut  oil  soap,  but  it  must  contain 
tallow,  which,  when  it  is  boiled  and  nearly  finished,  is  fitted 
or  ground  with  a  weak  solution  of  carbonate  of  soda,  the 
quantity  depending  upon  the  dr^^ness  of  the  grain  soap  after 
its  separation  with  salt.  It  has  a  smooth  wax-like  appear- 
ance, and  being  highly  detergent,  is  very  popular  on  the  con- 
tinent of  Europe  as  a  laundry  soap. 


Bran  is  boiled  with  2  per  cent,  of  soda-lye  in  a  large 
amount  of  water  and  strained.  It  is  supposed  to  be  useful  for 
washing  cotton  cloths  for  printing. 


The  soap  is  cut  into  shavings  and  melted  in  the  ox-gall 
at  a  moderate  heat,  evaporating  until  of  proper  consistency. 
The  ox-gall  is  prepared  by  boiling  it  with  10  to  12  parts 
wood  spirit  and  straining. 

Scouring  Balls. 

White  curd  soap   .       .       .       .16  kilog.  (35.2  lbs.  ) 

Pearl  ash  3     "      (  6.6  "  ) 

Oil  of  juniper       .       .       .       .     1^    "      (  3.3  "  ) 

Mixed  together,  having  previously  added  a  little  water  to 
the  soap  and  pearl  ash  to  dissolve  them  by  a  moderate  heat; 
add  the  oil  of  juniper  and  mould  into  balls. 


Wax  or  Bleaching  Soap. 


Bran  Soap. 


Ox-Gall  Soap  for  Scouring  Woollens. 


Purified  ox-gall 
White  curd  soap 


1  part 

2  " 


MISCELLANEOUS  USEFUL  SOAPS. 


385 


French  Scouring  Soap. 


Curd  soap 
Water  . 


1^  kilog.  (3.3  lbs.  ) 
20  litres.  (5.3  gals.) 


Oil  of  turpentine  .  .  .  .16  grms.  (0.56  oz.  ) 
Aqua  ammonia     .       .       .       .33     "      (1.16  *'  ) 

The  soap  is  dissolved  by  heat  in  half  the  water,  and  the 
other  ingredients  added.  This  is  used  as  a  soft  soap  for  the 
laundry. 


Good  rosin  soap  .  .  .  .16  kilog.  (35  lbs.  ) 
Oil  of  turpentine  .  .  .  .  2  "  (  4.4  "  ) 
Sal  ammoniac      .       .       .       .     1     "      (  2.2  "  ) 

Melted  toscether  and  formed  into  cakes  used  for  removins: 
ink,  wine,  or  vinegar  stains. 


Good  rosin  soap  .  .  .  .16  kilog.  (35  lbs.  ) 
Pipeclay,  or  fuller's  earth,  in  powd.    1^    "      (  3.3  "  ) 

Melt  the  soap  in  a  water-bath,  and  when  perfectly  melted 
add  the  powdered  earth.  This  is  used  as  an  erasive  for 
grease  and  other  stains  on  clothing.  It  is  usual  to  cut  it 
into  small  cakes  with  printed  directions. 

Labor-saving  Soap. 

Good  rosin  soap    ....     1    kilog.  (2.2  lbs.) 

Sal  soda  f    "       (1.65  "  ) 

Water  33    litres  (8.7 gals.) 

One  litre  or  1  quart  is  added  to  each  5  gallons  of  water 
used  in  washing.  It  is  particularly  applicable  for  use  with 
hard  water. 


This  is  a  hard  soap  usually  made  on  farms,  using  the 
kitchen  or  other  greases  to  make  a  soft  soap  with  wood-ash 
lye,  boiling  well  to  a  clear  paste,  and  cutting  with  culinary 


Scouring  Tablets. 


Erasive  Soap. 


Country  Soap. 


25 


386  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

salt.  The  only  art  is  in  making  a  clear  glossy  paste  before 
cutting,  when  the  soap  is  generally  allowed  to  cool  and  rest 
for  a  day,  when  the  cakes  of  soap  are  removed  from  the  sur- 
face and  cut  up  and  dried  in  the  shade. 


Domestic  Soft  Soap. 

Grease  3.64  kilog.  (8  lbs.  ) 

Potash  2.7      "     (6    "  ) 

Water  113  litres  (30  gals.) 

The  potash  is  dissolved  in  a  portion  of  the  water.  About 
a  third  of  the  grease  is  added  and  heat  applied.  It  is,  when 
mixed,  put  into  a  barrel  in  the  cellar  and  the  rest  of  the 
water  added  in  portions  for  seven  days,  and  after  repeated 
stirrings  for  a  fortnight  it  is  ready  for  use. 

Shaker  Soft  Soap. 

Strong  lye  from  wood  ashes  .  .  45  litres  (12  gals.) 
Grease  2.83  "      (6  pints.) 

Water  sufficient  to  make  up  the  113  litres  (30  gallons). 
Manipulation  is  similar  to  that  for  the  domestic  soft  soap. 


Borax  Soft  Soap. 

V7hite  fats   45.4  kilog.  (100  lbs.) 

Soda  lye,  15©  B   45.4    *'  (100  "  ) 

Potash  lye,  lOO  B.       .       .       .  27.3    "  (  60  "  ) 

Solution  of  borax,  lOo  B.     .       .  6.8    "  (15  ") 

The  soda  lye  is  added  to  the  melted  grease  and  heated  till 
it  forms  a  clear  liquid  or  is  combined,  when  the  potash-lye 
and  borax  solution  are  added.  Et  should  be  a  semi-solid  trans- 
lucent paste,  and  is  usually  sold  in  quart  cans,  and  is  quite 
popular. 


Lubricating  Soap. 

Palm  oil,  crude   .2  parts. 

Tallow  1  part. 

Solution  carb.  soda,  15^  1  " 


Melt  together. 


MISCELLANEOUS  USEFUL  SOAPS. 


387 


Agricultural  Soap  (Whale-oil  Soap) 

Whale-oil  foot      .       .       .       .       .       .       .2  parts. 

Soda  lye,  30^  B  1  part. 

Made  in  the  cold  way.  Whale-oil  foot  is  the  residuum 
left  ill  refilling  the  oil.  This  soap  is  useful  for  destroying 
insects  on  plants. 

Fig  Soap 

Is  another  name  for  the  grained  soft  soap,  so  named  because 
it  resembles  the  seeds  of  fisis. 


Pearl  Soap  Powder. 


Curd  soap,  dried  and  powdered 

Sal  soda,  " 

Silicate  of  soda      "  '* 


4  parts. 


Made  as  dry  as  possible  and  intimately  blended. 


Curd  soap, 
Soda  ash. 
Silicate  of  soda, 
Borax,  crude, 


Borax  Soap  Powder. 

in  powder 


5  parts. 
3  " 
2  " 
1  part. 


Each  ingredient  is  thoroughly  dried  and  all  mixed  together 
by  sieving. 


London  Soap  Powder. 


Yellow  soap 
Soda  crystals 
Pearl  ash 
Sulph.  soda  . 
Palm  oil 


6  parts. 
3  " 
1^  " 

H  " 
1  part. 


These  ingredients  are  combined  as  well  as  possible  without 
any  water,  and  they  are  spread  out  to  dry  and  then  ground 
into  a  coarse  powder. 

Thus,  in  an  infinite  degree  can  the  variety  of  soap  pow^ders 
be  multiplied.  They  are  adapted  for  hard  waters,  as  their 
excess  of  alkali  neutralizes  the  lime. 


388  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Belgian  Soft  Soap. 


Tallow  . 
Cocoa-nut  oil 


350  kilog.  (770  lbs.) 
150    "     (330  "  ) 


Palm  oil,  bleached  .       .       .       .    100    "     (220  "  ) 

This  quantity  of  fats  is  boiled  in  a  caustic  potash-lye  of 
20°  B.  until  perfectly  saponified.  Water  is  added  to  keep 
the  proper  consistency.  This  is  a  favorite  soap  for  manu- 
facturers of  cloths  and  woolens. 


To  a  good  white  soda  cold  soap  yet  warm  add  a  solution  of 
ammonia  alum,  say  10  per  cent,  of  8°  B.  solution,  before  put- 
ting in  the  frames.  The  ammonia  will  be  set  free  and  im- 
prove the  detersive  qualities  of  the  soap. 


Under  this  name  a  pure  soap  is  made  with  oleic  acid  and  * 
caustic  potash-lye,  care  being  taken  to  obtain  a  neutral  pro- 
duct.   It  is  boiled  with  a  moderately  strong  lye  until  the 
proper  consistency  is  reached. 


Make  as  usual.    Used  for  washing  in  sea-water. 

In  our  section  on  toilet  soaps,  we  shall  give  a  large  num- 
ber of  formulas  of  soaps  that  properly  belong  to  that  depart- 
ment. From  a  great  number  of  useful  domestic  and  manu- 
facturer's soaps,  we  have  selected  what  we  consider  most 
reliable,  and  such  as  will  give  the  intelligent  manufacturer 
hints  towards  many  more,  should  he  have  occasion  to  make 
them. 


Ammoniated  Soap. 


Medicated  Soft  Soap. 


Marine  Soap. 


Cocoa-nut  oil  soap 
Fuller's  earth  . 
Calcined  soda  ash 


100  parts. 
50  " 
50  " 


TOILET  SOAPS. 


389 


SECTIOI^T  XIX. 

TOILET  SOAPS. 

The  increased  demand  and  production  of  this  class  of 
soaps,  has  made  their  manufacture  one  of  the  most  important 
of  which  it  is  our  office  to  treat  and  explain.  The  writer,  in 
his  connection  with  the  fat  industry  for  nearly  forty  years,  can 
readily  trace,  in  the  United  States,  the  different  improvements 
made  during  that  period  in  this  art:  from  the  time  when 
the  chandler  made  the  tallow  curd  soap,  and  marbled  it  with 
vermilion,  perfumed  it  with  sassafras,  formed  it  into  squares 
or  rounded  it  into  balls,  and  when  this  was  a  standard  for  a 
domestic  toilet  soap.  This  soap,  being  made  of  tallow  and 
soda- lye,  soon  became  so  hard  that  it  was  almost  impossible 
to  coax  a  lather  from  it,  even  after  a  previous  soaking  in 
water. 

Then,  later,  the  perfumer  bought  the  different  domestic 
soaps,  remelting,  perfuming,  and  forming  into  cakes  with  the 
plane,  wrapping  them  in  gorgeous  wrappers,  and  applying  to 
them  names  to  suit  the  prevailing  taste.  Then  again,  when, 
some  twenty  years  ago,  toilet  soaps  were  made  by  the  cold  or 
extempore  process,  the  product  was  very  inferior,  the  result  of 
a  very  imperfect  knowledge  of  the  proper  method  and  mani- 
pulation. But  since,  the  progress  has  been  a  steady  improve- 
ment to  the  present  time,  when  we  may  be  said  to  stand  on 
nearly  equal  ground  with  the  older  nations,  our  products 
comparing  favorably  with  any  others. 

Owing  to  the  prestige  of  time  and  many  local  facilities, 
Europe  may  produce  many  superior  soaps,  and  may  be  said 
to  be  without  rivals  in  certain  kinds;  yet  in  as  far  as  the 
usual  toilet  soaps  are  concerned,  we  are,  owing  to  our  many  • 
improvements  in  machinery,  the  abundance  of  superior  ma- 


390  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


terials,  and  the  attention  to  the  chemical  rules  of  the  art, 
producing  goods  that,  for  prices  and  quality,  compete  with 
any  in  the  world. 

The  fabrication  of  toilet  soaps  presents  but  few  changes 
from  those  already  given  in  the  making  of  domestic  and 
manufactured  soaps,  except  a  greater  care  in  the  selection  of 
the  raw  materials,  which  should  all  be  of  the  best  quality. 
The  fatty  bodies  and  the  bases  should  be  purified  as  much  as 
possible,  the  oils  and  fats  from  all  odor  and  impurities,  the 
alkali  from  all  foreign  salts  and  carbonic  acid,  and  made  as 
caustic  as  possible. 

For  making  a  good  and  pure  toilet  soap,  due  care  in  puri- 
fying the  fats  and  oils  is  perhaps  the  first  stage  of  the  pro- 
cess. When  the  manufacturer  has  the  opportunity  and  the 
facility  to  render  his  own  greases,  there  will  be  much  advan- 
tage as  insuring  their  purity  and  enhancing  the  quality  of 
his  soaps  very  much. 

To  Render  and  Purify  the  Grease, — Fat  of  good  quality  and 
very  fresh  must  be  selected,  the  membranes  of  which  are 
carefully  removed.  This  operation  being  performed,  it  is 
spread  on  a  strong  piece  of  oak  wood  and  strongly  beaten  to 
open  the  adipose  cells  in  which  the  grease  is  contained;  by 
this  means  the  grease  is  more  easily  and  quickly  extracted. 
The  fat  is  then  washed  five  or  six  times  in  cold  water,  the 
water  being  renewed  each  time.  This  operation  is  performed 
in  large  buckets  two-thirds  filled  with  water;  the  water  of 
the  last  washing  must  remain  clear  and  limpid.  The  object 
of  these  washings  is  to  remove,  as  completely  as  possible,  the 
coloring  and  bloody  parts  which  are  adherent  to  the  grease, 
and  which  would  color  and  alter  it  during  the  trying  out,  and 
would  render  its  perservation  uncertain  and  difiicult.  These 
washings  being  finished,  the  fat  is  drained  on  clean  cloths,  then 
melted  in  a  copper  kettle,  in  which  is  a  quantity  of  water  about 
equivalent  to  one-third  of  the  weight  of  the  fat.  All  being 
thus  ready,  heat  the  kettle,  and,  when  the  grease  is  melted, 
add  from  five  to  seven  ounces  of  pure  salt  for  every  45.5  kilog. 
(100  pounds.)  Boil  for  eight  or  ten  minutes,  and  as  in  boil- 
ing a  scum  is  formed,  it  is  carefully  removed  with  a  skim. 


TOILET  SOAPS. 


391 


mer.  The  melting  being  finished,  decant  the  liquid  grease 
into  large  copper  vessels  having  a  conical  form  ;  but  to  have 
clean  grease,  pass  it  through  a  hair  sieve  which  prevents  the 
solid  and  insoluble  substances  from  passing  through.  Let  it 
rest  for  two  or  three  hours ;  during  this  time  the  water  sep- 
arates, carrying  with  it  the  dirt  contained  in  the  grease.  It 
is  then  carefully  decanted  and  put  back  into  the  scoured 
kettle,  and  melted  with  water,  to  which  are  added  a  few  quarts 
ofrose  or  orange-flower  water.  Heat  anew,  and  when  the  grease 
is  melted,  add  to  it  two  ounces  of  pure  powered  alum  for 
100  pounds  of  grease,  boil  gently  for  eight  or  ten  minutes, 
and  carefully  remove  the  scum  formed  on  the  surface  of  the 
grease.  Then  turn  off  the  heat,  cover  the  kettle  with  care, 
which  is  essential  for  keeping  the  mass  at  an  elevated  tem- 
perature. Let  this  stand  for  eight  or  ten  hours,  or,  what 
is  surer,  until  the  grease  begins  to  whiten  and  solidify  on  the 
sides  of  the  kettle.  When  in  this  state,  decant  it  into  clean 
barrels  and  keep  for  use. 

As  the  last  portions  of  grease  which  swim  on  the  water  are 
less  white  and  pure  than  the  first,  they  are  kept  separate  to 
prepare  soaps  of  second  qualit3^  The  grease  thus  purified 
may  be  kept  a  long  time  without  alteration,  and  forms  the 
base  of  toilet  soaps  of  the  first  quality.  There  are  other 
methods  for  attaining  this  end.  When  the  greases  are  ob- 
tained reasonably  pure,  one  of  the  simplest  is  to  melt  in  the 
kettle  the  requisite  soap  grease,  and  when  at  about  45°  C. 
(113°  F.)  to  add  about  two  per  cent,  of  strong  alkali  of  36°  to 
40°  B.,  stirring  some  time  and  shutting  off  the  heat.  A  soap 
Avill  be  formed  of  the  impure  fat,  and  will  sink  to  the  bottom, 
carrying  almost  all  of  the  other  impurities  down  with  it, 
when  the  clarified  grease  can  be  carefully  separated. 

In  boiling  a  soap  and  separating  with  culinary  salt,  fats 
less  pure  may  be  used,  as  the  impurities  are  usually  carried 
down  with  the  sub-lye,  which  separation  can  be  repeated 
till  the  soap  is  pure  and  colorless,  and  to  the  improvement  of 
its  quality.  But  in  the  soaps  by  the  extempore  processes,  all 
the  contents  of  the  fats  are  retained  in  the  soap  as  well  as 


392  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


the  glycerine,  hence  the  necessity  of  a  purified  fatty  body 
to  produce  a  good  and  pure  product. 

Toilet  soaps  are  now  nearly  all  made  by  this  latter  (cold) 
process,  for  several  reasons :  first,  because  the  alkalies  are  now 
obtainable  in  a  much  purer  state  than  in  former  years;  sec- 
ondly, because,  by  the  facilities  of  improved  machinery,  their 
quality  is  improved  ;  thirdly,  because  they  retain  their  form 
much  better  than  boiled  soaps,  which  in  drying  warp  and 
become  misshapen;  fourthly,  because  by  means  of  these  new 
appliances  they  can  be  manipulated,  milled,  colored,  per- 
fumed, plotted,  etc.,  in  a  cold  state;  finally  their  appearance 
is  much  more  attractive.  All  these  manifold  labors  tend  to 
the  improvement  of  a  soap,  as  the  more  it  is  worked  the 
more  perfect  is  the  union  of  its  ingredients,  and  consequently 
the  more  perfect  is  the  soap. 

Cocoa-nut  oil  has  for  many  years  formed  one  of  the  chief 
constituents  of  toilet  soaps  on  the  continent  of  Europe,  and, 
when  its  natural  rancid  smell  is  not  objected  to,  is  a  valuable 
material,  as  it  has  some  desirable  properties,  making  a  very 
white  and  emollient  soap,  but  it  is  not  possible  to  remove  all 
its  unpleasant  odor.  For  this  reason  it  is  not  used  in  the 
better  qualities  of  soaps,  nor  in  but  a  small  proportion,  and 
then  the  best  quality  of  Cochin  China  oil  is  preferred. 

Cotton-seed  oil  is  another  ingredient,  that  has  lately  claimed 
much  attention  as  a  material  for  toilet  soaps,  and  has  some 
peculiarities  similar  to  the  cocoa-nut  oil  without  its  unpleasant 
smell.  We  have  used  it  in  combination  with  tallow,  castor 
oil,  lard,  etc.,  and  the  resulting  soap  was  quite  satisfactory. 
Being  a  cheap  material,  it  would  appear  that  it  should  attract 
great  attention  from  the  manufacturers  of  toilet  soap. 

Toilet  Soaps  by  Boiling. 

We  have  in  this  work  given  so  many  particulars,  as  to  the 
processes  of  boiling  soap,  that  it  is  scarcely  necessary  here  to 
repeat  them,  as  all  of  these  methods  apply  equally  to  soaps 
for  toilet  purposes,  but,  as  we  desire  to  make  this  work  as  com- 
plete as  possible,  we  will  give  some  examples,  remarking  that 


TOILET  SOAPS. 


393 


nearly  all  the  appurtenances  heretofore  given  apply  to  this 
branch  also,  and  repeating  the  necessity  of  securing  pure  and 
neutral  products  and  materials. 

In  many  large  manufactories  it  is  quite  common  to  have 
the  boiled  soaps  in  stock  in  several  kinds,  which  are  mixed 
in  certain  proportions  to  form  the  various  kinds;  thus  they 
make  a  white  soap,  a  palm  soap,  a  half-palm  with  rosin,  a 
cocoa-nut  oil  soap,  etc.  These  are  usually  kept  in  a  cool 
room  or  cellar,  and  when  wanted  they  are  re-melted,  or  milled, 
colored,  perfumed,  etc.  To  make  one  of  these  soaps  by 
boiling  we  give  the  formulas  for  the  half-palm  soap  with 
rosin,  and  the  process  will  apply  to  the  rest  except  the  cocoa- 
nut  oil  soap  which  is  differently  made. 

Half-Palm  Soap. 

Either  of  the  following  formulas  may  be  used: — 

White  tallow   900  pounds. 

Palm  oil   400  " 

Cocoa-nut  oil   200  " 

Yellow  rosin   100  " 

1600 

Tallow   700  pounds. 

Palm  oil   300  " 

Cotton-seed  oil   400  " 

Rosin   200  " 

1600  " 

Lard   550  pounds. 

Tallow  oil   400  " 

Cotton-seed  oil   450  " 

Rosin  200  " 

1600  " 

The  proportions  of  these  substances  are  not  fixed,  and  vary 
according  to  the  uses  for  which  the  soap  is  destined.  In 
England  this  soap  is  prepared  with  common  tallows  and  an 
addition  of  rosin.  In  France  where  it  is  used  only  for  toilet 
purposes,  it  is  better  attended  to,  and  its  purification  is  more 


394  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


complete.  The  above  formulas  give  a  soap  of  superior  quality, 
and  the  use  of  which  is  very  advantageous  in  the  preparation 
of  toilet  soaps.  The  palm  oil  may  be  bleached  or  not,  but 
must  always  be  purified. 

Fasting. — By  a  gentle  heat,  melt  the  tallow  and  oils  in 
a  kettle  of  a  capacity  of  at  least  2633  litres  (696  gallons). 
When  melted,  pour  into  the  kettle  378  litres  (100  gallons) 
of  new  lye  at  8°  or  10°  B. ;  heat  slowly  and  gradually,  stir- 
.ring  from  time  to  time,  and  when  the  ebullition  begins, 
moderate  the  action  of  the  heat,  to  avoid  too  rapid  a  reac- 
tion in  the  mass.  After  continuing  the  ebullition  for  about 
four  hours,  pour  little  b}^  little  on  the  paste  from  thirty-five 
to  fifty  gallons  of  new  lye  at  15°  or  18°,  and  incorporate  it 
by  stirring  for  fifteen  minutes.  This  being  done,  continue 
to  boil  for  three  hours,  or  rather  until  the  paste  appears  quite 
homogeneous  and  has  acquired  a  certain  consistency.  Then 
a  new  quantity  of  thirty-five  gallons  of  lye  at  20°  may  be 
added,  and  after  a  new  ebullition  of  two  hours  the  first  opera- 
tion is  finished. 

Separation. — The  pasting  being  finished,  the  heat  is  stopped 
off,  and  after  a  few  hours'  rest,  pour  into  the  kettle  a  limpid 
lye  of  coction,  i.  e.^  salted  lye  at  20°  to  25°,  or  a  new  lye  con- 
taining salt  in  solution.  While  one  man  pours  in  the  lye, 
another  stirs  the  paste  all  the  time.  When  the  quantity  of 
salt  lye  introduced  into  the  kettle  is  suflScient,  the  soap  is 
transformed  into  small  grains,  and  the  lye  separates  abun- 
dantly. After  resting  five  or  six  hours,  draw  off  the  lye. 
About  two-thirds  of  the  lyes  which  have  been  used  are  drawn 
off ;  they  have  a  yellowish  color,  and  mark  when  cold  from 
15°  to  16°.  The  pasty  mass  left  in  the  kettle  has  a  fine  yel- 
low color. 

Coction. — The  coction  of  this  soap  is  very  little  different 
from  that  of  pure  palm-oil  soap.  Like  the  latter,  it  is 
effected  with  new  and  caustic  lyes  of  soda  marking  25°  or 
28°.  When  the  operation  is  done  in  two  services,  lyes  at 
18°  or  20°  are  used  for  the  first  service,  and  lyes  at  25°  or 
28°  for  the  second.    When,  on  the  contrary,  the  coction 


TOILET  SOAPS. 


395 


is  finished  in  a  single  operation,  lyes  at  25°  are  used.  This 
last  process  is  the  quickest  and  most  economical. 

The  lyes  being  drawn  off,  pour  into  the  kettle  from  567 
to  661.5  litres  (150  to  175  gallons)  of  new  lye  at  25°  ;  heat, 
and  give  a  gentle  boiling,  for  in  the  first  hours  the  soap 
dilates  and  swells  considerably.  Its  surface  is  then  covered 
with  an  abundant  scum,  which  gradually  disappears  only  as 
the  coction  progresses.  It  is  necessary  to  stir  from  time  to 
time  during  the  whole  of  the  operation.  This  agitation  is 
very  important,  for  it  accelerates  the  coction  of  the  soap. 
When  the  soap  has  been  gently  boiled  for  three  or  four 
hours,  the  heat  may  be  increased  without  fear  of  burning 
the  soap.  Generall}^,  after  eight  or  ten  hours  of  ebullition 
with  lye  at  25°  the  soap  is  completely  boiled.  The  scum 
has  entirely  disappeared,  or  there  remains  very  little  on  the 
surface  of  the  soap,  which  then  has  the  form  of  hard  and 
dry  grains.  When  these  grains  are  pressed  between  the 
fingers,  they  form  thin  and  hard  scales.  The  rosin  has  been 
added  at  the  beginning  of  the  coction,  so  as  to  saponify  it 
completely.  When  the  soap  is  suflaciently  boiled,  which  is 
known  when  it  forms  scales,  stop  off  the  heat,  let  it  rest  a 
few  hours,  draw  off  the  lye,  and  proceed  to  the  fitting. 

Fitting. — Two  operations  are  necessary  to  completely  re- 
fine the  soap.  The  first  has  for  its  object  to  soften  the 
grains  of  soap,  and  to  separate  the  greater  part  of  the  free 
alkali  and  saline  matters ;  the  second  has  for  its  object  to 
completely  dissolve  the  grains  of  soap  and  precipitate  the 
coloring  and  heterogeneous  substances,  and  the  excess  of 
caustic  lye  it  contains. 

First  lAquefadion. — When  the  lye  has  been  drawn  off, 
pour  into  the  kettle  378  litres  (100  gallons)  of  new  lye  at 
8°  or  9°,  and  heat  gradually  until  boiling,  being  careful  to 
stir  the  mixture  well.  When  the  grains  of  soap  have  be- 
come soft,  cease  the  stirring  ;  and,  to  complete  the  precipita- 
tion of  the  strong  lye  contained  in  the  soap,  boil  for  five  or 
six  hours,  or  even  eight  hours.  As  by  such  a  long  ebullition 
the  grain  of  the  soap  has  a  tendency  to  be  formed  again, 
pour  from  time  to  time  into  the  kettle  a  few  pails  of  lye  at 


396  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


2°  and  even  pure  water.  It  is,  however,  necessary  that  the 
soap  should  be  always  separated  from  the  lye ;  this  is  ascer- 
tained by  pouring  some  into  a  glass,  and  if  so,  the  lye  pre- 
cipitates at  the  bottom  of  the  glass.  It  is  important  and 
essential  to  have,  during  the  whole  operation,  the  lye  sepa- 
rated from  the  soap,  to  obtain  the  separation  of  the  strong 
lye  mixed  with  the  paste.  When  this  result  is  obtained, 
stop  off  the  heat  and  cover  the  kettle.  Let  it  rest  six  hours, 
then  introduce  the  soap  into  another  kettle  and  proceed  to  a 
second  liquefaction. 

Second  Liquefaction, — Whatever  has  been  the  care  taken  in 
the  first  liquefaction,  the  soap  has  not  been  completely  de- 
prived of  all  its  causticity — it  always  contains  a  certain  quan- 
tity of  caustic  alkali,  which  must  be  eliminated  to  obtain  a 
pure  product.  This  is  the  object  of  the  second  liquefaction. 
But  to  obtain  all  the  good  results  this  operation  may  produce, 
substitute  for  the  caustic  lyes  of  soda  ash,  a  non  caustic  solution 
of  crystals  of  soda.  By  its  extreme  purity  and  the  absence  of 
causticity,  this  solution  completely  purifies  the  soap,  depriv- 
ing it  of  all  its  caustic  parts.  Pour  into  the  new  kettle  about 
136  litres  (36  gallons)  of  a  solution  of  crystals  of  soda  at  4J° 
or  5°,  and  heat  to  a  temperature  near  the  boiling  point.  Then 
introduce  the  soap  from  the  first  kettle  into  the  second,  being 
careful  not  to  draw  any  of  the  sub-lye.  This  being  done,  boil 
thQ  mixture  gently  for  four  or  five  hours,  being  careful  to  stir 
from  ti  me  to  time.  By  the  ebullition  with  weak  lyes  (aqueous 
solution  of  crystals  of  soda),  the  soap  entirely  loses  its  granu- 
lar appearance,  and  becomes  syrupy,  fluid,  and  homogeneous. 
As  in  the  first  liquefaction,  a  scum  is  formed  on  the  surface 
of  the  soap,  and  this  scum  is  more  considerable  on  account 
of  the  greater  dilatation  of  the  paste.  As  by  evaporation  the 
lye  concentrates, add  from  time  to  time  very  small  portions  of 
water,  so  as  to  keep  the  paste  always  fluid.  The  heteroge- 
neous coloring  and  saline  impurities  will  be  precipitated  by 
resting.  The  soap  must  not  contain  too  much  water,  for  in 
this  case  it  would  be  too  long  in  hardening.  The  signs  by 
which  it  is  ascertained  that  the  paste  is  sufliciently  liquefied, 
are  manifested  by  a  slightly  blackish  coloration  which  proves 


TOILET  SOAPS. 


397 


that  the  black  soap  has  been  precipitated  to  the  bottom  of 
the  kettle,  and  is  brought  up  in  the  mass  by  the  ebullition. 
When  these  characteristics  have  been  observed,  the  operation 
is  finished ;  stop  off  the  heat,  cover  the  kettle  and  let  it  rest 
eighteen  or  twenty  hours.  By  resting,  the  black  soap  pre- 
cipitates with  the  lye,  and  the  pure  soap  is  between  it  and 
the  scum.  After  eighteen  or  twenty  hours'  rest,  uncover  the 
kettle  and  remove  the  scum  on  the  surface  of  the  soap.  Re- 
move the  pure  soap  and  introduce  it  into  the  frames,  passing 
it  through  a  metallic  wire  sieve;  all  the  foreign  bodies  in  the 
soap  remain  on  the  sieve: — 

When  all  the  pure  soap  has  been  introduced  into  the  frames 
stir  it  well  till  cold ;  this  manipulation  is  necessary  to  make 
it  homogeneous.  By  operating  as  we  have  indicated,  the 
above  quantities  of  fatty  matters  generally  give : — 

Soap-scum,  from  64  to  73  kilog.        141  lbs.  to  161  lbs. 
Pure  soap,     "    954  "  983    "         2100   "   "  2160  " 
Black  soap,   "    227  "  273    "  500   "   "   600  " 

The  scum  and  black  soaps  are  mixed  in  the  next  operation 
or  used  for  a  common  soap.  The  half-palm  soap  has  a  very 
pure  yellow  color  when  manufactured  with  good  materials. 
It  has  also  a  good  odor,  and  is  useful  for  making  many  kinds 
of  soaps,  such  as  honey,  glycerine,  marshmallow,  etc. 

For  a  palm  soap  for  stock  and  for  toilet  soap,  we  refer  to 
the  formulas  previously  given  for  palm  soaps,  and  for  this 
purpose  advise  extra  care  in  selecting  the  materials. 

For  a  white  soap  for  toilet  purposes  use  the  same  processes 
for  tallow,  grain  or  curd  soap,  given  elsewhere,  using  only 
the  whitest  and  sweetest  greases  and  purest  alkali. 

The  cocoa-nut  oil  soap  for  toilet  purposes  should  have  a 
different  manipulation.  This  oil  not  being  saponifiable  in 
w^eak  lyes,  it  is  always  necessary  to  use  lyes  of  28°  to  36° 
B.  They  need  not  be  entirely  caustic,  as  this  oil  can  also  be 
saponified  in  carbonated  lyes,  though  it  of  course  takes  more 
of  them  and  a  longer  time.  For  this  soap  it  is  now  customary 
to  use  a  portion  of  lard,  cotton-seed  oil,  or  any  other  white 
grease  or  oil,  but  the  cocoa-nut  oil  for  toilet  soaps  should  be 


398  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


the  best  Cochin  China  oil.  By  using  a  certain  proportion  of 
potash  lye  the  soap  retains  a  more  plastic  consistency  and  is 
much  improved.   The  amount  is  usually  from  6  to  10  per  cent. 

"White  Soap  from  Cocoa-nut  Oil. 

To  prepare  182  kilog.  (400  lbs.)  of  this  soap,  introduce  into 
a  kettle  of  a  capacity  of  200  to  250  gallons  200  pounds  of 
pure  white  cocoa  oil ;  add  afterwards  200  pounds  of  colorless 
and  perfectly  limpid  lye  at  30°. 

All  being  ready,  heat  the  kettle,  and,  to  accelerate  the 
combination  of  the  substances,  stir  well  from  time  to  time. 
Under  the  influence  of  heat  the  material,  which  at  first  was 
in  the  form  of  grains,  softens  and  becomes  liquid.  Continue 
to  heat  slowly  and  gradually  until  the  combination  between 
the  oil  and  alkali  is  effected,  which  generally  takes  place 
when  the  ebullition  begins. 

When  properly  made,  the  soap  has  the  appearance  of  a 
fluid,  homogeneous,  and  syrupy  paste.  Its  color  is  amber 
white.  It  is  useless  to  boil  it ;  stop  off  the  heat  and  draw 
off  the  soap  into  the  frame. 

If,  on  the  contrary,  it  happens  when  the  mixture  begins 
to  boil  that  a  certain  quantity  of  oil  swims  at  the  sur- 
face of  the  paste,  it  may  be  combined  wnth  the  saponified 
mass,  by  adding  ten  to  twelve  pounds  of  cocoa-nut  oil  soap. 
The  same  result  may  be  obtained  by  adding  eight  or  ten 
quarts  of  pure  water.  After  stirring  a  few  minutes,  the 
homogeneity  of  the  soap  is  re-established,  and  the  combina- 
tion of  the  substances  is  perfected.  The  heat  is  then  stopped, 
and  the  soap  drawn  off  into  the  frame.  After  five  or  six 
days,  the  soap  is  firm  enough  to  be  taken  out  of  the  frame. 

Obtained  by  the  above  process,  this  soap  is  very  white, 
does  not  contain  any  excess  of  alkali  or  oil,  and  may  be 
employed  for  toilet  uses.  From  the  quantities  indicated 
above,  from  396  to  420  pounds  of  soap  are  obtained,  accord- 
ing to  the  quantity  of  water  added.  The  operation  lasts 
about  one  hour. 

It  is  not  necessary  to  give  further  formulas  for  the  different 


TOILET  SOAPS. 


399 


soaps  that  this  useful  oil  may  form  in  any  judicious  mixture 
with  other  fats,  as  they  are  almost  without  number,  and,  with 
the  hints  already  given,  any  others  may  be  manipulated. 
Where  a  colored  soap  is  desired,  palm  oil  is  a  very  suitable 
combination. 

The  soaps  here  given  may  be  called  stock  soaps;  for  from 
them  nearly  all  kinds  of  toilet  soaps  can  be  formed,  by  a 
mixture  of  the  different  kinds  in  suitable  proportions,  mill- 
ing, mixing,  coloring,  plotting,  moulding,  and  perfuming  to 
suit  the  kinds  needed.  As  in  our  formulas  these  soaps  may 
be  frequently  called  for,  it  were  well  to  give  them  some 
attention.  But  as  we  haVe  before  remarked,  almost  all  toilet 
soaps  are  now  made  by  the  cold  or  extempore  process,  when 
the  soaps  are  colored  and  perfumed  in  the  kettle,  or  what  is 
better,  when  they  are  run  into  the  frames,  or  still  better,  when 
put  in  a  crutching  machine,  such  as  we  have  described  else- 
where. 


400 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


SECTIO^T  XX. 

TOILET  SOAPS  BY  THE  COLD  PROCESS. 

Extempore  Soaps. 

These  processes  have  become  so  universal  for  the  fabrication 
of  all  toilet  soaps,  that  they  require  special  attention  at  our 
hands.  Beyond  what  has  been  already  given  in  the  methods 
for  making  the  cold  or  extempore  soaps,  there  is  but  little  to 
add,  except  in  the  care  in  selecting  the  purest  materials,  or 
making  them  perfectly  pure  before  manipulation,  and  giving 
due  regard  to  the  proper  equivalents  of  the  fatty  bodies 
with  the  alkalies  to  form  a  neutral  soap. 

For  fine  toilet  soaps  there  are  many  desirable  greases  and 
oils,  that  can  be  used  to  much  advantage,  their  price  being 
usually  too  high  for  the  ordinary  soaps,  but  in  this  class  of 
soaps,  the  price  generally  obtained  justifies  their  employ- 
ment. Thus  almond  oil,  castor  oil,  olive  oil,  butter,  lard, 
tallow  oil,  beef-marrow,  cocoa-butter,  bleached  palm  oil,  palm- 
kernel  oil,  sesame  oil,  and  other  such  like  fats  and  oils  of 
good  quality  could  be  advantageously  used  in  a  judicious 
admixture,  for  it  seems  that  such  a  mixture  produces  a  more 
desirable  soap  than  any  one  used  alone  will  do,  the  properties 
of  one  so  blending  with  the  other  as  to  produce  the  most 
satisfactory  results. 

From  the  facility  with  which  this  soap  can  be  made,  it  is 
quite  unnecessary  to  make  the  stock  soap  as  mentioned  and 
described  in  our  last  chapter.  For  a  small  quantity  can  be 
made  as  well  as  a  larger  ;  indeed  it  is  not  convenient  generally 
to  make  over  five  to  eight  hundred  pounds  at  a  time,  and  the 
kind  of  soap  needed  can  be  at  once  prepared,  colored,  and  per- 
fumed at  the  finish  as  described.  Some  manufacturers  prefer 
to  mill  all  their  soaps,  and  color  and  perfume  while  milling; 


TOILET  SOAPS  BY  THE  COLD  PROCESS. 


401 


there  are  many  advantages  in  this.  The  color  is  better, 
more  uniform,  there  is  no  loss  of  color  or  perfume  by  heat, 
there  is  a  more  complete  blending  of  the  materials  in  the 
soap,  which,  when  finished,  retains  its  form,  color,  and  per- 
fume for  any  reasonable  length  of  time. 

Again,  for  the  superfine  soaps  of  the  finest  odors,  made 
from  the  oils  or  pomades  perfumed  with  flowers  by  the  pro- 
cess of  enfleurage,  elsewhere  described,  such  as  rose,  jasmine, 
orange-flower,  etc.,  this  extempore  process  is  indispensable, 
as  a  boiling  heat  would  cause  not  only  a  loss  of  perfume,  but 
an  undesirable  change  in  it. 

Many  mechanical  appliances  have  been  made  to  facilitate 
this  process ;  which  usually  have  a  stirrer  or  twirl  placed  in 
the  kettle  or  cylinder,  and  are  a  great  advantage  in  manipu- 
lating ;  they  are  illustrated  in  our  former  chapter  on  cold  soap 
for  domestic  use. 

The  use  of  filling  in  toilet  soaps  must  not  always  be  con- 
sidered an  adulteration,  for  there  are  some  substances  that 
may  be  regarded  as  an  advantage,  or  at  least  in  the  light 
of  ameliorators.  Thus  dextrine  in  moderate  quantity  gives 
smoothness  without  injury,  while  the  mucilage  of  gum  traga- 
canth  gives  both  smoothness  and  emollience,  which  are 
desirable  qualities  in  the  best  soaps.  Soluble  glass,  while  it 
cheapens  the  cost  of  soaps,  does  not,  if  used  in  moderation, 
and  properly  combined,  injure  its  detersive  quality  or  its 
value  for  use.  It  is,  however,  often  used  in  such  quantities  as 
to  become,  with  other  adulterations,  a  means  of  unprincipled 
sophistication,  giving  a  bad  character  to  much  of  the  toilet 
soap  of  commerce.  Rosin,  on  the  other  hand,  if  added  to 
other  good  materials,  may  have  certain  advantages,  especially 
with  a  medium  grade  of  soap,  giving  it  a  soluble  and  lather- 
ing property,  which  is  always  popular.  A  portion  of  potash 
lye  also  gives  this  soluble  property. 

The  alkalies  for  toilet  soaps,  as  we  have  said,  should  be  of 
the  purest,  and  should  receive  strict  investigation  (see  Alka. 
limetry).  While  the  caustic  lyes  of  commerce  are,  as  a  rule, 
sufficiently  pure  for  ordinary  soaps  if  freshly  prepared  and 
made  caustic,  for  the  finer  grade  of  soaps,  it  is  most  desirable 

26 


402  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


to  prepare  the  caustic  lyes  from  the  crystallized  carbonate  of 
soda ;  from  its  mode  of  manufacture  having  less  foreign  salts 
than  any  other  form  of  soda.  To  prepare  this  alkali  it  is  only 
necessary  to  extract  the  carbonic  acid  with  the  purest  lime 
attainable,  and  form  a  solution  of  12  to  15°,  and  then  concen- 
trate by  evaporation  to  the  desired  strength,  putting  into  well 
filled  and  stoppered  bottles  or  carboys  that  it  may  not  ab- 
sorb any  carbonic  acid,  and  that  it  may  be  always  ready  for 
immediate  use. 

In  making  the  soaps  by  the  cold  process  our  formulas  gene- 
rally call  for  a  lye  at  36°  B.  Now  this  is  subject  to  some  modi- 
fication, as  there  are  many  circumstances  and  conditions  where 
a  lye  of  less  strength  would  be  more  advantageous.  When  a 
weaker  lye  is  used,  there  must  of  course  be  more  of  it  (the 
tables  given  will  show  how  much);  and  again  the  different 
greases  act  somewhat  differently  in  connection  with  the 
weaker  or  stronger  lye;  all  of  this  must  be  gained  by  expe- 
rience, for  it  would  be  impossible  without  a  knowledge  of 
all  the  conditions  and  materials  to  give  exact  details. 

With  these  preliminary  remarks  we  think  we  can  now 
proceed  to  give  the  necessary  formulas,  and  begin  with 

White  Soap  by  the  Cold  Process. 

To  obtain  white  toilet  soap  of  the  first  quality,  employ  white 
grease.    The  following  are  the  best  proportions  to  use: — 

Pure  white  grease  160  lbs. 

Lye  of  crystals  of  soda  at  360  B.      .       .      .    80  " 

240 

Saponify  as  follows :  Melt  the  grease  in  a  cast-iron  kettle 
of  a  capacity  of  about  75  gallons.  To  operate  with  great 
precision,  dip  a  thermometer  into  the  melted  grease,  and 
when  the  temperature  has  reached  from  45^  to  50°  C.  (113° 
to  122°  F.)  pour  in  slowly  the  80  pounds  of  lye  at  36°  B.,  stir 
the  mixture  all  the  time  with  an  iron  spatula  until  the  entire 
saponification  of  the  materials.    It  is  important  not  to  raise 


TOILET  SOAPS  BY  THE  COLD  PROCESS. 


403 


the  temperature  above  122°  F.,  for  in  that  event  a  part  of  the 
1  ve  would  separate  from  the  fatty  substances. 

For  the  quantities  indicated  above,  the  operation  lasts  about 
two  hours.  When  the  saponification  is  finished,  which  is 
ascertained  when  the  fatty  matters  are  exactly  combined  with 
the  lye,  run  the  soap  into  a  frame.  While  the  soap  is  yet 
soft,  if  almond  soap  is  wanted,  it  may  be  perfumed  with  12 
ounces  of  oil  of  bitter  almonds,  and  4  ounces  of  oil  of  lemon  for 
each  100  pounds  of  soap.  For  the  above  mixture  may  be 
substituted  13  ounces  of  artificial  oil  of  bitter  almonds,  but 
this  last  oil  communicates  to  the  soap  a  yellowish  shade. 
This  soap  may  be  also  perfumed  with  the  following  mixture 
for  100  pounds: — 

Oil  of  vervain 
"  lavender 
"  bergamot 
"  lemon 
' '  thyme 

The  oils  must  be  added  as  soon  as  the  soap  is  poured  into 
the  frame ;  and  well  crutched  to  mix. 

A  remarkable  phenomenon,  not  produced  with  soaps  boiled 
on  the  lye,  occurs  five  hours  after  the  soap  is  poured  nearly  cold 
into  the  frame;  a  spontaneous  reaction  takes  place,  which 
raises  the  temperature  to  about  82.2°  C.  (180°  F.).  Under  the 
influence  of  this  temperature  the  difierent  constituent  princi- 
ples of  the  soap  combine  more  directly  and  intimately,  and  the 
product  is  better.  It  is  important  to  hasten  that  reaction  by 
closely  covering  the  frame. 

A  few  days  after  the  mass  of  soap  is  cooled  and  solidified, 
take  it  out  of  the  frame  and  divide  it  into  cakes,  which  are 
dried  in  the  drying  room,  if  necessary.  The  quantities  of 
substances  used  give  from  236  to  238  pounds  of  soap,  or  149 
per  100  of  fat. 

When  well  prepared,  this  soap  is  of  a  very  pure  white,  not 
very  alkaline,  and  produces  an  abundant  lather  with  water. 

Rose  Soap. — The  white  soaps  can  be  colored  with  four  or 
five  ounces  of  vermilion,  and  perfumed  with 


2|  ounces. 

2 

2 

2 

3 


404 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Oil  of  rose  2  ounces. 

"     geranium  4  *' 

"     cinnamon  1  ounce. 

"     cloves       .      .       .      .      .       .       •     2  " 

"     bergamot  2  ounces. 

to  each  100  lbs. 

Windsor  Soap  can  also  be  made  of  the  white  soaps  or  with 
the  half-palm  soap,  coloring  with  caramel  or  other  means, 
and  perfuming  each  100  pounds  with 


Oil  of  cinnamon  4  ounces. 

cloves  .       .       .       .       .       .       .1  ounce. 

"     caraway  1  " 

"     sassafras  2  ounces. 

"     bergamot  2 


Yellow  Soap. — This  soap,  which  has  a  fine  yellow  color,  is 
obtained  with  tallow,  palm,  and  cocoa  oils.  The  following 
proportions  give  excellent  results: — 


White  tallow  50  lbs. 

Cocoa-nut  oil  30  " 

Palm  oil  20 

Lye  of  soda  at  360  B.        .      .      .        50  to  52  " 


Melt  the  tallow  and  other  fatty  substances  in  a  sheet-iron 
kettle,  add  the  lye,  and  operate  as  for  white  soap.  If  the 
color  is  not  dark  enough,  add  a  solution  of  annotto,  pre- 
pared by  boiling  one  ounce  of  annotto  or  cadmium  yellow, 
in  one  quart  of  lye  of  soda  at  10°,  boil  five  minutes  and  pass 
through  a  cloth. 

Perfume  this  soap  with  the  following  composition,  calcu- 


lated for  150  lbs.  of  soap: — 

Oil  of  lavender   10  ounces. 

"     lemon   2  " 

*'     vervain    .       .       .       .       .       .       .  1^  '* 

"     peppermint   |  ounce. 

"     neroli  petit  grain   1  " 

White  Windsor  Soap. 

Take 

White  tallow  80  lbs. 

Cocoa  oil  40  " 

Lye  of  crystals  of  soda  at  30°  .       .       .       .  68 
"      "       *'     potash  at30o      .      .       .  12  " 


TOILET  SOAPS  BY  THE  COLD  PROCESS. 


405 


Melt  the  greases  in  a  kettle  of  a  capacity  of  about  fifty 
gallons.  When  the  fusion  is  complete  and  the  temperature 
is  at  about  35°  C.  (95°  F.),  introduce  the  lyes  little  by  little, 
stirring  all  the  time,  and  continue  until  the  substances  form 
a  homogeneous  paste.  The  operation  lasts  about  fifteen  min- 
utes.   This  soap  is  perfumed  with 


Oil  of  carvi  (caraway)   4  ounces. 

"     bergamot   6  " 

"     Portugal   2  " 

*'     cloves   ^  ounce. 

"     lavender   4  ounces. 

"     thyme   2  " 


Add  the  oils  to  the  soap  a  few  minutes  before  introducing 
into  the  frames.  When  the  soap  has  become  solid  divide  it 
into  cakes  weighing  from  two  to  four  ounces,  according  to 
the  size  of  the  mould.  The  soap  thus  prepared  is  of  a  very 
pure  white,  and  does  not  contain  too  much  caustic  alkali. 

Honey  Soap  can  also  be  made  of  the  half-palm  soap  with 
rosin,  by  putting  in  the  pan  just  before  turning  into  the 
frame  8  ounces  of  citronella  oil  and  2  ounces  of  lemon-grass 
oil  to  each  100  pounds. 

Glycerine  Soap  can  be  perfumed  in  the  same  way;  for  each 
100  pounds  take 


Oil  of  cassia   2  ounces. 

"     caraway   1  ounce. 

"     lavender   4  ounces. 

"     mirbane   1  ounce. 


Let  both  of  these  soaps  be  a  bright  yellow,  the  last  of  a 
somewhat  darker  shade  to  distinguish  it. 

Marsh-mallow  Soap  can  be  made  by  an  admixture  of  the 
palm  and  the  half-palm  soap,  and  perfumed  to  each  100 
pounds  with 


Oil  of  lavender   6  ounces. 

"     lemon-grass   4  " 

"     peppermint  ^  ounce. 

*'     petit  grain  ^  " 


To  make  a  good  rose  soap  take  equal  parts  of  the  white 


406  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


and  cocoa-nut  oil  soap,  and  color  100  pounds  with  12  ounces 
of  French  vermilion,  and  perfume  with 

Oil  of  rose  geranium   4  ounces. 

"     rose   1  ounce. 

"     cinnamon   1  " 

"     bergamot   2  ounces. 

Old  Brown  Windsor  Soap. 

This  popular  soap,  when  properly  prepared,  is  made  in  the 
following  manner :  Take  of  boiled  palm  soap  and  half-palm 
soap  each  50  pounds;  put  in  the  stripper,  and  make  into 
thin  shavings,  and  spread  upon  sheets  of  strong  paper  to 
dry;  when  dry,  melt  in  a  marine  bath  with  a  small  portion 
of  an  .aromatic  water,  and  when  it  is  again  hard  enough  pro- 
ceed to  cut  it  up  and  strip  it  as  before,  drying  it  again  and 
remelting  and  adding  caramel  to  color ;  and  after  the  third 
operation  add  the  following  perfume  to  the  100  pounds: — 

Oil  of  bergamot   4  ounces.  • 

"     caraway   2  " 

"     cassia   2  " 

"     lavender   8  " 

"     cloves   1  ounce. 

"     petit  grain   1  " 

Mould  or  cut  into  small  square  cakes,  and  wrap  them  in  a 
neat  paper  wrapper. 

Brown  Windsor  soap  owes  its  fine  emollient  properties  to 
the  amount  of  labor  employed  in  its  manufacture,  for  it  is 
almost  needless  to  say  that  the  more  soap  is  worked  and 
handled,  and  melted  and  remelted,  the  better  it  becomes. 
This  soap  is,  in  large  establishments,  often  made  of  the 
scraps  of  all  other  kinds  of  soaps  that  accumulate  from 
moulding  and  other  manipulations,  but  of  course  these  do  not 
generally  produce  so  good  a  soap. 


Half  Boiled  Soap — Swiss  Soaps. 


We  employ  the  latter  term  to  denote  the  soaps  that  are 
usually  boiled  in  one  lye  and  by  one  operation,  and  which 


TOILET  SOAPS  BY  THE  COLD  PROCESS. 


407 


not  being  separated  retain  all  their  glycerine  and  are  classed 
among  the  extempore  soaps.  There  are  several  ways  of 
working  more  or  less  perfect;  we  .will  describe  two.  First, 
when  a  soap  is  composed  of  one  part  cocoa-nut  oil  and  two 
parts  of  other  greases,  the  cocoa-nut  oil  is  saponified  by  the 
cold  process  separately,  while  the  other  greases  are  boiled 
with  a  weaker  lye  of  12°  to  16°  B.,  separated,  and  the  lye 
withdrawn.  The  two  soaps  are  then  mixed  and  gently  boiled, 
being  careful  that  they  do  not  separate,  and  that  the  due  pro- 
portion of  alkali  and  water  is  used  to  form  a  neutral  soap. 

By  the  second  method  the  process  is  simplified,  and  with 
careful  manipulation  the  result  is  equally  satisfactory,  and 
the  yield  is  greater,  100  pounds  of  fats  forming  210  to  220 
pounds  of  marketable  soap.  It  is  customary  to  make  these 
toilet  soaps  with  a  percentage  of  potash  \ye  with  the  soda,  say 
about  10  per  cent.  In  this  process  the  whole  amount  of  fats 
or  oils  is  at  once  placed  in  the  kettle,  and  the  lyes  are  made 
rather  strong,  15  to  20°  B.  One  half  is  put  with  the  grease 
and  heated  to  a  gentle  boil,  which  should  cause  a  combination 
of  the  ingredients  if  the  lye  is  not  too  strong.  When  this 
lye  has  been  absorbed,  the  rest  of  the  lye  is  added  from  time 
to  time  until  all  is  taken  up,  and  the  froth  disappears,  and 
the  soap  has  the  proper  consistency,  and  is  of  a  gelatinous 
appearance,  when  it  is  run  into  the  frames,  crutched,  colored 
and  perfumed,  while  it  is  still  soft.  This  operation  occupies 
about  four  hours. 

In  forming  the  Swiss  soaps  a  certain  amount  of  skill  is 
very  essential,  and  various  precautions  must  be  exercised  in 
having  the  due  equivalents  of  fat  and  alkali,  and  the  proper 
proportion  of  water  that  the  soap  is  to  retain,  and  the  final 
adjustment  of  the  soap  at  the  finish  to  insure  its  proper 
admixture  and  neutral  character.  Having  a  portion  of  cocoa- 
nut  oil  in  their  composition,  they  will  hold  a  large  percentage 
of  water,  and  can  also  be  filled  with  salt  water,  silicate  of 
soda,  etc.  etc.  Care  must  also  be  taken  that  the  soap  does 
not  grain;  if  it  does,  a  few  gallons  of  hot  water  stirred  in 
will  generally  restore  it  to  a  pasty  condition. 


408  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

Kurten^s  Table, 


Showing  the  composition  and  product  of  soap  by  the  cold  process  from  con- 
centrated  lye^  and  mixture  of  cocoa  oil  with  palm  oil,  lard  and  tallow. 


IS 

o 

d 

CO 

® 

00 

05 

Soap. 

o 

ej 
O 

o 

a 

« 

« 

9 
bo 

(D 

w 

iS 

"o 

bo 
« 

s 

O 

E-t 

o 
O 

1^ 

CO 

Ph 

be 

o, 

Cocoa-nut,  No.  1  . . 

100 

56 

36 

153 

Paris  toilet,  round 

20 

30 

's 

31 

36 

5 

36 

87 

io 

Kf\ 

oo 

1  K(\ 
lOU 

Windsor,  square. . . 

66 

34 

77 

30 

13 

30 

185 

Shaving,  No.  1  . . . . 

00 

or 
33 

or 
34 

33 

120 

27 

214 

Shaving,  No.  2  

33 

34 

33 

120 

27 

12 

12 

226 

Washing,  No.  1  . . . 

60 

40 

or 

or 

125 

27 

25 

12 

244 

30 

40 

30 

Washing,  No.  2  . . . 

40 

60 
or 
60 

40 

135 

27 

50 

15 

278 

Ordinary  cocoa  oil . 

or 

100 
or 

10 

90 
or 
90 

10 

225 

21 

75 

12 

400 

MISCELLANEOUS  TOILET  AND  MEDICATED  SOAPS.  409 


SECTIOi^'  XXI. 

MISCELLANEOUS  TOILET  AND  MEDICATED  SOAPS,  WITH 
FORMULAS. 

We  have  in  our  two  preceding  sections  given  the  pro- 
cesses for  forming  the  usual  kinds  of  soaps  used  for  making 
toilet  soap,  and  those  that  are  at  once  made,  colored,  and 
perfumed  at  the  finish  and  are  ready  to  be  cut  up  and  dried 
previous  to  moulding.  We  here  give  formulas  for  making 
the  various  soaps  now  known  in  commerce,  with  suitable 
hints  towards  many  new  styles. 

As  we  have  said,  the  manipulation  of  soaps  for  the  toilet  is 
an  important  part  in  the  production  ;  to  make  them  market- 
able, good  and  uniform,  well  colored  and  smoothly  finished, 
nicely  perfumed,  and  neatly  packed.  To  aid  these  ope- 
rations, various  appliances  are  used,  and  much  apparatus  is 
needed,  and  in  our  next  section  we  will  give  a  careful  de- 
scription with  illustrations  of  all  the  latest  machines  now 
in  use  and  which  greatly  facilitate  the  manufacture,  saving 
time  and  labor,  besides  improving  the  quality  and  appearance 
of  the  products. 

Many  of  the  finer  soaps  have  to  be  made  from  the  raw 
materials,  though  most  of  them  are  made  from  the  stock 
soaps  before  mentioned.  The  different  formulas  will  show 
in  some  instances  that  the  soaps  can  be  remelted  to  produce 
the  best  results,  though  many  and  most  can  be  mixed,  colored 
and  perfumed  by  repeated  passage  through  the  mill,  and  this 
kneading  that  they  receive  will  tend  to  benefit  them. 


Cold  Cbeam  Soap. 


White  soap 
Spermaceti  soap 
Oil  of  almonds  . 
Caustic  potash,  QO 
Gum  tragacanth . 


30  lbs. 
20  " 
^Ib. 

1  " 

2  ounces. 


410  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


To  manipulate,  strip  up  the  two  soaps,  place  them  in  the 
hopper  of  the  mill,  dissolve  the  gum  by  previous  soaking  in 
a  little  water,  mix  with  the  oil  and  lye  to  a  uniform  con- 
sistency, then  stir  into  the  soap  and  grind  in  the  mill  until 
thoroughly  combined.  Care  should  be  taken  to  have  it  as 
white  as  possible.    Perfume  the  above  with 


Oil  of  bergamot   5  ounces. 

"     cloves   1  ounce. 

"     nutmegs  .      .   1  " 

"     thyme   3  ounces. 

"     bitter  almonds   1  ounce. 


Bouquet  Soap. 

White  curd  soap  60  lbs. 

"     cocoa-nut  oil  soap  40  " 


Dextrine    ........  3  " 

Perfume  with 

Oil  of  cedrat   6  ounces. 

"     asarum   2  " 

"     cloves   2  " 

"     thyme   3  " 

"     petit  grain   2  " 


Color  a  light  yellow  with  cadmium  yellow,  manipulate  as 
for  the  cold  cream  soap,  dissolving  the  dextrine  in  its  weight 
of  warm  water. 


Lemon  Soap. 

White  soap   50  lbs. 

Starch   2  " 

Perfume  with 

Oil  of  lemon   4  ounces. 

"     bergamot   2  " 

"     lemon-grass   2  " 

"     cloves   1  ounce. 

Color  light  yellow  wnth  cadmium  yellow. 


miscellaneous  toilet  and  medicated  soaps. 
Orange  Soap. 

White  soap        .       .       '       .       .       .       .50  lbs. 
Starch  2  " 

Perfume  with 

Oil  of  orange  peel  8  ounces. 

"     cinnamon  ^  ounce. 

"     thyme     .      ,      .      ...      .    2  ounces. 

Color  dark  yellow  with  naphthaline  yellow. 

Elder  Flower  Soap. 

Half-palm  soap  100  lbs. 

Dextrine  3  " 

Perfume  with. 

Oil  of  bergamot  .8  ounces. 

lavender  ,      .    2  " 

"     thyme  2  " 

"     cloves  1  ounce. 

"     cassia  2  " 

"     almonds  2  " 

Color  light  green  with  Guinet's  green. 

Heliotrope  Soap. 

White  curd  soap  80  lbs. 

Palm  soap  20  " 

Starch  4  " 

Perfume  with 

Oil  of  rosemary  .       ...       .       .       .4  ounces. 

"     thyme  2  " 

"     rose  geranium  3  " 

"     cloves  2  " 

"     almonds  1  ounce. 

Balsam  of  Peru  3  ounces. 

Color  light  purple  with  a  red  and  blue  color. 

Frangipanni  Soap. 

Palm  soap  30  lbs. 

White  soap  20  " 

Dextrine    .      .  3  " 


412 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Perfume  with 


Oil  of  bergamot   4  ounces. 

"     neroli   2  " 

"     santal   2  " 

Tincture  vanilla   4  *' 

"         civet   4  *' 


Color  light  hrown  with  tincture  of  catechu. 

For  toilet  soaps  made  with  other  soaps,  these  recipes  will 
give  a  proper  idea  and  hints  for  any  kind  the  manufacturer 
will  desire. 

Superfine  Soaps. 

We  will  now  proceed  to  give  the  formulas  for  fine  and 
superfine  soaps,  to  which  we  would  recommend  the  addition 
of  a  little  wax  as  giving  a  consistency  and  smothness,  besides 
improving  their  quality. 

Ambergris  Soap  (Ambrosial  Soap). 


Grease  perfumed  with  ambergris  and  musk     .  25  lbs. 
Jasmine  pomade  of  flowers,  No.  24  .      .      .  10  " 
Rose         "       u  "...  10  " 

Beeswax  1  lb. 

Gum  tragacanth  3  ounces. 

Caustic  soda  lye,  33o  B  25  lbs. 


Color  light  brown  with  caramel. 

This  soap  is  made  of  select  materials  by  the  cold  process, 
and  after  being  made  is  allowed  a  few  days  to  dry  before 
milling ;  the  musk  and  ambergris  have  to  be  added  to  the 
grease  some  weeks  before,  frequently  melting  and  stirring. 

Benzoin  Soap. 

Lard  with  benzoin   30  lbs. 

Cocoa-nut  oil   10  " 

Tallow   10  " 

Soda  lye,  350  B   26  " 

Gum  tragacanth .      .  ....  2  ounces. 


MISCELLANEOUS  TOILET  AND  MEDICATED  SOAPS.  413 


Perfume  with 

Oil  of  bergamot  8  ounces. 

"     lavender   3  " 

"     pimento  1  ounce. 

Flowers  of  benzoin    .       .       .       .       .       .3  ounces. 

Tincture  of  benzoin  3  " 


Saponify  in  the  usual  way.  The  lard  with  benzoin  is 
made  by  infusing  the  lard  with  the  powdered  gum,  two 
ounces  to  the  pound  for  a  month,  occasionally  melting  and 
Stirring.    Melt  and  strain  off  the  clear  lard  before  using. 

JoNQUiLLE  Soap  (superfine). 


Orange-flower  pomade,  No.  24  .       .      .      .20  lbs. 
Tuberose  "        "         ....  10  " 

Jasmine  "        "         .       .       .       .  10  " 

Castor  oil  10  " 

White  wax  IJ  " 

Gum  tragacanth  2  ounces. 

Caustic  soda  lye,  360  B  27  lbs. 


Saponify  as  carefully  as  possible,  avoiding  too  much  heat. 
This  soap  will  be  a  light  yellow.  To  enhance  the  color  add 
a  little  anatoline. 

MiLLEFLEUR  SOAP. 


Lard  with  vanilla   20  lbs. 

*'       ambergris   10  " 

Rose  pomade  (aux  fleurs)  No.  24   .       .       .  10  " 

Butter  of  cocoa   10  " 

Chocolate   2  " 

Caustic  lye,  36°  B   26  " 

Perfume  with 

Oil  of  orange  (Portugal)   8  ounces. 

"     lavender   4  " 

"     cloves   2  " 

"     nutmegs  1  ounce. 

Tincture  of  musk   4  ounces. 


The  chocolate  will  give  the  proper  color.  Operate  with 
care,  and  you  will  have  a  very  fine  soap. 


414  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Savon  a  la  Marechale  (surfin). 


Lard  with  musk   10  lbs. 

"     "    ambrette   10  " 

Pomade  (aux  fleurs)  No.  24  : 

Cassia,  jasmine,  and  rose,  of  each  .       .       .  10  " 

Olive  oil  1  lb. 

White  wax  2  lbs. 

Gum  tragacanth  2  ounces. 

Caustic  lye,  360    28  lbs. 

Saponify  carefully  and  color  with  a  little  caramel. 

Savon  Hygienique  (extra  fine). 

Orange  flower  pomade.  No.  24       .      .      .10  lbs. 

Rose  pomade.  No.  24  5  " 

Palm  oil  (bleached)   20  " 

Cocoa  butter  5  " 

Olive  oil   10  " 

White  wax      .       .       ,      .       .       .      .     1  lb. 

Caustic  lye,  380  B   24  lbs. 

Gum  tragacanth  2  ounces.  . 

Perfume  with 

Oil  of  santal  2  ounces. 

"     geranium  2  " 

"     valerian  (rect.)  1  ounce. 

"     melisse  1  " 

"     orange  ;       .     4  ounces. 

"     thyme    .  2  " 

Avoid  too  much  color ;  the  soap  should  have  a  yellowish- 
brown  that  needs  no  addition. 

Savon  a  la  Violette  de  Parme. 

Violette  pomade,  24    20  lbs. 

Eose  "      24   10  " 

Cassia  24   10  " 

Palm  oil  (bleached)   10  " 

Soda  lye,  360B   25  " 

Gum  tragacanth  2  ounces. 


Give  it  a  purple  color,  not  too  dark. 


MISCELLANEOUS  TOILET  AND  MEDICATED  SOAPS. 


415 


Lettuce  Soap. 


Lard  with  lettuce   20  lbs. 

Cassia  pomade,  24   10  " 

Spermaceti   5  " 

Castor  oil   5  " 

Palm  oil  (bleached)   10  ^' 

Caustic  lye,  360  B   26  " 

Gum  tragacanth   3  ounces. 

Perfume  with 

Oil  of  bergamot   6  ounces. 

"     thyme   2  " 

"     valerian   1  ounce. 

"     cloves   1  " 


Color  light-green  with  Guinet's  green.  The  lard  with 
lettuce  is  made  by  melting  the  lard  with  its  own  weight  of 
lettuce  leaves,  keeping  it  at  the  melting  point,  about  32.2°  C. 
(90°  F.),  for  some  hours,  or  until  the  leaves  have  parted 
with  their  color  and  juice,  then  strain  off  for  use. 

Cucumber  Soap. 
Operate  as  for  lettuce  soap,  using  the  fruit. 

MoussELiNE  Soap. 
Similar  to  marechale  soap,  using  another  color. 

Savon  de  Muguet.  Lily  Soap. 
Similar  to  jonquille  soap,  keeping  it  as  white  as  possible. 

Rose-leaf  Soap  (extra  fine). 


Rose  pomade  (aux  fleurs)  No.  24    .      .      .20  lbs. 

Lard   20  " 

Cocoa-nut  oil   10  " 

White  wax   2  " 

Soda  lye,  360B   20  " 

Potash  lye,  SQo  B   12  " 

Gum  tragacanth   3  ounces. 


416  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Perfume  with 

Oil  of  roses   2  ounces. 

"     geranium   2 

"     rhodium   1- ounce. 

"     bergamot   2  ounces. 

"     cinnamon  (Ceylon)      .      .       .       .  ^  ounce. 

Color  with  aniline  (fast  red)  a  light  pink. 

Violet  Soap  (yellow). 

Cocoa-nut  oil   20  lbs. 

Palm  oil   20  " 

Tallow  oil   10  " 

Soda  lye,  360  B.   26  " 

Orris  root  in  fine  powder   4  " 

Perfume  with 

Oil  of  lemon   4  ounces. 

"     rhodium   2  " 

"     thyme   2 

Tincture  of  musk   4  " 

Color  with  cadmium  yellow. 

Vanilla  Soap  (superfine). 

Lard  with  vanilla    ......  30  lbs. 

Cocoa  butter   10  " 

Palm  oil   10  " 

Caustic  lye,  360  B.   26  " 

Wax   2 

Starch   .  2  " 

Perfume  with 

Tincture  of  vanilla   4  ounces. 

"      "  musk   2  " 

"       "  ambergris   2  " 

Oil  of  rose   ^  ounce. 


Lard  with  vanilla  is  prepared  by  adding  the  vanilla  to  the 
lard  (1  oz.  to  the  lb.),  keeping  it  at  a  moderate  heat  for  some 
days,  straining,  etc. 

Rose  Windsor  Soap 

Is  best  made  with  the  white  soap  as  a  body,  coloring  red, 
and  perfumed  nicely  with  any  of  the  numerous  formulas  as 
here  given. 


MISCELLANEOUS  TOILET  AND  MEDICATED  SOAPS.  417 


YiOLET  Windsor  Soap. 

Take  any  good  soap,  say  a  mixture  of  white  and  palm 
soap,  color  yellow,  and  perfume  nicely. 


Musk  Windsor  Soap. 

A  palm  soap  perfumed  with  the  tinctures  of  musk, 
civet,  and  vanilla,  and  colored  brown  with  malline  brown 
and  well  milled.  These  Windsor  soaps  are  usually  wrapped 
in  neat  wrappers. 

As  French  soaps  have  a  just  reputation  for  good  quality, 
we  append  a  list  of  names  of  some. 


French  Toilet  Soaps. 


Savon  a  Pambre. 


Savon  a  la  verveine. 


an  bouquet. 

(( 

a  la  tubereuse. 

a  la  fleur  d'orange. 

(( 

a  la  limette. 

a  I'acacia. 

(( 

au  lilas. 

a  la  julienne. 

aux  millefleurs. 

au  narcisse. 

(( 

au  myrte. 

a  la  jaciuthe. 

a  la  marechale. 

a  la  jasmine. 

ii 

orientale. 

a  la  jonquille. 

Occident. 

au  vitevert. 

des  Indies. 

a  Toeillet. 

n 

a  la  balsamine. 

a  la  mousseline. 

i( 

au  geranium. 

a  la  mignonette. 

<i 

a  la  dalie. 

aux  fleurs  d'ltalie. 

<( 

a  la  campanule. 

a  la  palma  rosa. 

(( 

a  la  camelie. 

a  la  rose-blanche. 

n 

aux  fleurs  de  champ. 

a  la  lavende. 

<( 

a  la  rose. 

au  chypre. 

(( 

a  la  rose  du  Provence. 

a  I'iris. 

n 

a  la  rose  de  Bengale. 

a  Theliotrope. 

n 

a  la  giroflee. 

a  la  violette. 

( ( 

au  patchouli. 

au  pois  de  senteur. 

au  santal. 

a  la  noisette. 

(( 

au  muse. 

a  I'amande  amare. 

27 


418  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Medicated  Soaps. 

Soap  is  a  valuable  vehicle  for  the  administration  of  many 
medicinal  and  curative  substances,  and,  when  the  article  is 
not  altered  or  injured  by  the  natural  excess  of  alkali  in  all 
soaps,  it  is  a  useful  means  to  that  end.  Many  cosmetics  are 
also  added  to  soap. 

Carbolic  Soap. 

Half-palm  soap   20  lbs. 

Starch  1  lb. 

Carbolic  acid  (crystals)  1  ounce. 

Oil  of  lavender  2  ounces. 

"    cloves  1  ounce. 


Medicated  Tar  Soap. 

Cocoa-nut  oil   20  lbs. 

Tallow     .       .   10  " 

Juniper  tar  5  " 

Soda  lye,  40©  B   15  " 

The  greases  should  first  be  saponified,  and  the  juniper  tar 
added  at  the  finish  ;  perfume  can  be  added,  though  fine  per- 
fume would  be  lost  in  the  strong  odor  of  the  tar. 


Sulphur  Soap. 

Take  any  good  hard  soap,  the  half-palm  for  instance,  and 
melt  carefully  with  dissolved  starch,  and  add  about  12  per 
cent,  of  lac  sulphur,  color  light  yellow  with  naphthaline 
yellow.    Perfume  to  fancy. 

Tooth  Soap. 

Tallow  soap,  white   20  lbs. 

Pumice  stone  (lixiviated)   ^  lb. 

Prepared  chalk   2  lbs. 

Starch      .      .       .       .      .       .      .       .  ^  lb. 

Perfume  and  color  to  suit.  The  soap  can  be  melted  or 
milled  and  the  ingredients  thoroughly  incorporated.  Any 
color,  perfume,  or  name  can  be  given  it. 


MISCELLANEOUS  TOILET  AND  MEDICATED  SOAPS.  419 


Thus  the  intelligent  soap-maker  can  prepare  any  kind  of 
medicated  soap  by  using  the  proper  proportion  of  the  sub- 
stance, taking  care  that  the  medicine  may  not  be  injurious 
to  the  skin  or  the  health. 

Tannin  Soap  with  3  per  cent,  of  tannic  acid. 

Salicylic  Soap  with  2  per  cent  of  salicylic  acid. 

Disinfectant  Soap  w^ith  carbolic  acid,  about  2  per  cent. 

Thymol  Soap  with  3  to  5  per  cent,  of  thymol. 

Croton  Oil  Soap  with  2  per  cent,  of  croton  oil. 

Benzoic  Acid  Soap  with  2  per  cent,  of  benzoic  acid. 

Castor  Oil  Soap  with  20  per  cent,  of  oil  with  the  other 
fats. 

Petroleum  Soap  with  20  per  cent,  of  the  petroleum  oil 
added  to  the  other  fats  before  saponification. 

Paraffin  Soap:  the  wax  is  added  to  the  amount  of  10 
per  cent,  to  the  fats  before  saponification. 

Creasote  Soap  with  2  per  cent,  of  creasote. 

Bromine  Soap  with  2  per  cent,  of  bromine. 

Iodine  Soap  with  2  per  cent,  of  iodine. 

Turpentine  Soap  with  6  per  cent,  of  oil  of  turpentine. 

Alum  Soap  with  10  per  cent,  of  finely  powdered  alum. 

Borax  Toilet  Soap  with  10  per  cent,  finely  powdered  borax. 

Mercurial  Soap  with  6  per  cent,  of  mercurial  ointment. 

Irish  Moss  Soap  with  5  per  cent,  of  Irish  moss  dissolved 
in  a  suitable  quantity  of  water  and  strained. 

Bran  Soap  with  10  to  20  per  cent,  of  bran. 

Cornmeal  Soap  with  10  to  20  per  cent,  of  maize  flour. 

Oatmeal  Soap  with  10  to  20  per  cent,  of  oatmeal. 

Camphor  Ice  Soap  with  5  per  cent,  of  camphor — added  to 
cold  cream  soap  would  be  very  suitable. 

Wax  Soap  with  10  per  cent,  of  wax  added  to  soap.  It  has 
some  good  and  useful  properties. 

Egg  Yolk  Soap. 

Cocoa-nut  oil   10  lbs. 

Tallow   10  " 

50  yolks  added  to  olive  oil  lo  make  .       .       .  5  " 

Soda  lye,  380  B   10^^ 


420  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Perfume  with  ' 

Oil  of  lemon   2^  ounces. 

"     sassafras   1^  ounce. 

"     thyme   ^  " 

"     cloves   ^  " 

Color  light  yellow.    Supposed  to  be  beneficial  to  the  skin. 
Bordhardt's  Herb  Soap. 

Olive-oil  soap   30  lbs. 

Palm-oil  soap   30  " 

Dextrine   3  " 

Perfume  with 

Oil  of  rosemary   3  ounces. 

"     lavender   1^  ounce. 

thyme   1^ 

*'     sage   1  " 

magnolia   1  " 

"     peppermint   1  " 

Color  blue. 

Beef  Marrow  Soap. 

Beef  marrow  (purified)   35  lbs. 

Soda  lye,  36^   10  " 

Potash  lye,  30O   3  " 

Saponify  in  the  usual  way,  color  yellow,  and  perfume  to 
suit. 

Spermaceti  Soap. 

Lard   30  lbs. 

Castor  oil   10  " 

Spermaceti   SO  " 

Soda  lye,  38°   25  " 

Potash  lye,  31o   8  " 


Avoid  all  color,  and  let  the  perfume  be  good. 

Shaving  Soaps  in  Tablets 

Are  made  with  a  perfectly  neutral  soap  having  a  certain  por- 
tion of  potash  in  the  lye.  The  walnut-oil  military  soap  is 
made  thus,  using  a  portion  of  nut  or  poppy  oil. 


MISCELLANEOUS  TOILET  AND  MEDICATED  SOAPS.  421 


Shaving  Compounds, 

Usually  put  up  in  china  boxes  or  mugs,  are  made  with  well- 
selected  soaps  with  some  potash  to  keep  them  plastic,  or  a 
mixture  of  soda  and  potash  soaps  is  made  and  perfumed 
in  the  mill.  The  variety  of  these  soaps  is  so  great  that  it  is 
useless  to  give  formulas;  these  hints  must  suffice. 


Floating  Soaps 

Are  made  from  soaps  that  are  composed  of  vegetable  oils  or 
greases,  which  are  stripped  and  melted  in  a  little  water,  the 
vessel  being  placed  in  a  marine  bath,  which  is  water  contain- 
ing a  portion  of  salt  and  which  can  be  heated  above  the  heat 
of  boiling  water.  The  kettle  has  a  mechanical  stirrer,  which 
causes  the  soap  to  foam  to  twice  its  bulk,  being  filled  with 
portions  of  air.  It  is  then  poured  into  shallow  frames,  and 
in  about  a  week's  time  cut  into  cakes. 


I^^'ymph  Floating  Soap. 

Palm  soap   30  lbs. 

Gocoa-nut  oil  soap   20  " 

Perfume  to  suit   8^  ounces. 


EosE  Floating  Soap. 

Olive-oil  soap   30  lbs. 

Cocoa-nut  oil  soap   20  " 

Color  with  vermilion   3  ounces. 

Perfume  with 

Oil  of  rose   a  ounce. 

"     bergamot      ......  4  ounces. 

"     geranium   2  " 


Powdered  Soaps. 

In  this  form  very  convenient  kinds  of  cosmetics  are  made 
and  used  for  a  variety  of  purposes,  as  a  dentifrice,  for  shav- 
ing, etc.  They  are  made  from  any  pure  soap,  which  is  cut 
into  shavings  and  thoroughly  dried,  when  they  are  ground 
and  sieved  into  the  finest  possible  powder,  perfumed  and  col- 


422  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


ored  in  any  way  desired.  They  should  be  put  up  in  well- 
stopped  bottles,  or  they  will  absorb  moisture  and  form  into 
lumps  again. 

Soap  Essences 

Are  usually  made  by  dissolving  a  potash  soap  in  a  suitable 
quantity  of  alcohol  of  85°,  perfuming  and  coloring  to  suit; 
the  colors  should  be  transparent  or  they  will  precipitate. 

Transparent  Toilet  Soaps 

Are  among  the  most  important  now  made,  and  owing  to  their 
neutrality  and  free  lathering  they  find  much  favor.  They 
are  also  attractive  in  appearance.  They  are  usually  made 
with  tallow,  cocoa-nut  oil,  and  castor  oil  in  varying  propor- 
tions. Eosin  also  is  added  in  the  cheaper  kinds,  though 
it  should  be  used  with  caution  as  it  tends  to  give  the  soap 
a  dark  color.  The  cold  process  is  now  the  usual  mode  of 
making  these  popular  soaps,  and  requires  great  exactitude 
in  the  proportions,  and  some  experience  and  skill  to  produce 
a  favorable  result.  It  is  needless  to  say  that  the  greases  and 
alkalies  should  be  in  their  purest  condition. 

Transparent  Soap  by  the  Cold  Process. 

Tallow,  or  a  suitable  mixture  .  .  95  kilog.  (209  lbs.) 
Caustic  soda  lye,  40O  B.  .  .  .  43  "  (  94.6  "  ) 
Alcohol  50    "     (110     "  ) 

To  the  melted  greases  add  one-half  the  alkali,  keeping  the 
heat  as  low  as  possible  or  about  48.9°  C.  (120°  F.);  when,  with 
constant  stirring,  the  fresh  lye  is  combined,  add  the  balance 
of  the  lye,  to  which  had  been  previously  added  the  alcohol, 
the  heat  being  well  regulated  ;  saponification  will  now  ensue 
very  rapidly  ;  then  add  the  perfume  and  color  and  pour  into 
the  frames,  cooling  very  gradually. 

The  transparency  will  not  be  perfect  until  it  has  been  ex- 
posed to  the  air  for  some  days;  this  quantity  of  soap  will 
require  about  a  kilog.  (2.2  lbs.)  of  mixed  essences  to  perfume 


MISCELLANEOUS  TOILET  AND  MEDICATED  SOAPS.  423 


it.    The  coloring  matter  if  added  should  be  perfectly  trans- 
parent.   These  soaps  are  seldom  colored. 

Transparent  Glycerine  Soap. 

Tallow  (mutton)       ....  20  kilog.  (44  lbs.) 

Cocoa-nut  oil   20    "  (44  "  ) 

Castor  oil   .       .       .       .       .       .  10    "  (22  "  ) 

Glycerin,  pure   10    "  (22  "  ) 

Caustic  lye,  40©  B   26    "  (57  "  ) 

Alcohol,  960   22    "  (48.4  "  ) 

Water  4f  "  (  9.9  "  ) 

Melt  the  grease  at  40°  C.  (104°  F.),  and  add  the  alkali  by 
slow  degrees,  keeping  the  heat  low  to  prevent  evaporation, 
and  stir  constantly.  When  the  lye  has  been  absorbed  after 
three  or  four  hours'  stirring,  add  the  alcohol,  which  should 
be  warmed,  stir  till  it  becomes  clear,  then  add  the  glycerine, 
and,  when  mixed,  the  water  and  perfume;  turn  into  the 
frame  pouring  slowly.  This  soap  if  carefully  made  is  a  very 
superior  one. 

Transparent  soaps  by  the  older  method  were  made  by  dis- 
solving tallow  curd  soap  in  its  own  weight  of  alcohol  85°, 
having  first  cut  the  soap  into  shreds  and  dried  it  thoroughly. 
The  ingredients  were  placed  in  a  still,  heated  by  a  water  bath, 
the  head  put  on,  and  the  condenser  or  worm  attached  and 
the  greater  portion  of  the  alcohol  recovered  which  can  be 
used  again  for  another  operation. 

There  is  a  still  simpler  method  of  making  transparent 
soaps,  and  which  is  generally  applied  to  the  cheaper  kinds. 
Tallow  and  rosin  soaps  are  stripped  or  planed  into  shavings 
and  dried  as  much  as  possible  in  heated  air,  and  alcohol  of 
95°,  of  which  latter  one-half  the  weight  is  taken  and  mixed 
in  the  water  bath  with  the  soap  which  is  soon  dissolved.  The 
heat  is  continued  for  some  time  to  evaporate  the  excess  of 
alcohol,  when  it  is  perfumed  and  framed.  This  soap  requires  ^ 
some  time  to  dry  before  it  becomes  properly  transparent. 


424  TEOHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Transparent  Soft  Soaps. 


Oleophane  or  Sapophane  is  made  in  the  same  manner  as  the 
kinds  above  mentioned,  substituting  potash  Ije  for  the  soda, 
and  is  valuable  for  shaving  and  other  toilet  purposes. 

Liquid  Glycerine  Soap  much  in  favor  is  made  thus: — 


The  ingredients  are  saponified  at  a  gentle  heat,  and  suffi- 
cient 95°  alcohol  added  to  make  the  soap  clear,  and  it  is  then 
filtered. 


Soaps  of  potash  are  among  the  most  valuable  cosmetics 
prepared  by  the  soap-maker  or  perfumer,  and  much  care 
should  be  exercised  in  having  the  purest  materials,  the 
greatest  cleanliness,  and  the  true  equivalents  of  the  parts,  as 
any  carelessness  in  them  particularly  deteriorates  the  quality 
of  the  product. 


To  prepare  this  soap  very  white,  operate  in  the  following 
manner: — 

Melt  in  a  sheet-iron  kettle  of  a  capacity  of  about  50  gal- 
lons, 50  pounds  of  white  fiit,  and  13  lbs.  of  cocoa  oil. 
When  the  fatty  matters  are  entirely  melted,  add  50  lbs.  of 
lye  of  potash  at  20°  or  21°  B.  Stir  all  the  time,  so  as  to  aid 
the  saponification,  the  temperature  being  kept  at  from  60  to 
65.5°  C.  (140°  to  150°  F.).  Under  the  influence  of  heat  and 
stirring,  the  aqueous  part  of  the  lye  evaporates  and  the  mix- 
ture acquires  a  thicker  consistency.  Sometimes  it  happens 
that  a  part  of  the  fatty  matters  separates ;  this  effect  is  pro- 
duced especially  when  the  temperature  of  the  mixture  is 


Oleic  acid  . 
Cocoa-nut  oil  (best)  . 
Potash  lye,  3oO  B.  . 
Glycerin  . 


85  kilog.  (187  lbs.) 
15  "  (33  "  ) 
53  (114  ) 

4.5   "  10 


Soft  Toilet  Soaps  of  Potash. 


Shaving  Creams. 


White  Soft  Soap. 


MISCELLANEOUS  TOILET  AND  MEDICATED  SOAPS,  425 


raised  near  the  boiling  point,  because  at  that  temperature,  con- 
centrated lyes  have  little  affinity  for  fatty  substances.  This 
effect  may  also  be  produced  by  the  insufficiency  of  alkali  in 
the  mixture.  In  the  first  case  the  homogeneity  is  re-estab- 
lished by  moderating  the  action  of  the  heat,  and  in  the  other, 
by  pouring  into  the  kettle  a  portion  of  strong  lye  necessary 
to  complete  the  saponification. 

This  first  stage  of  the  operation  lasts  about  four  hours. 
To  obtain  a  perfect  soap,  add  a  new  portion  of  10  lbs.  of  lye 
of  potash  at  16°  B.,  and  be  careful  to  keep  the  mixture  very 
uniform  by  a  continual  stirring.  Keep  the  temperature  be- 
low the  boiling  point,  and  as  much  as  possible  between 
60°  and  65.5°  C.  (140°  and  150°  F.). 

The  saponification  is  finished  when  the  paste  has  acquired 
a  very  thick  consistency  ;  at  this  point  turn  oflF  the  heat. 

Many  perfumers  prepare  this  soap  in  iron  kettles  with  a 
double  bottom,  heated  by  steam ;  some  use  silver  kettles 
which  are  preferable,  because  the  soap  will  retain  in  them 
all  its  whiteness. 

Fig.  63. 


The  above  figure  represents  a  jacket  or  kettle  with  a 
double  bottom,  heated  by  steam.  This  kettle  is  of  tinned 
copper,  and  may  be  used  also  to  purify  tallow  and  greases. 
The  operation  lasts  in  all  from  seven  to  eight  hours.  When 
the  soap  is  entirely  cooled  down,  pour  it  into  large  stone  jars 
in  which  it  is  kept  for  use.  Soft  soap,  as  obtained  by  the 
saponification  of  fatty  matters  by  potash,  has  not  that  bright 
and  nacreous  appearance  required  for  the  toilet.  To  obtain 
it  in  this  state  it  is  ground  in  a  marble  mortar,  and  aroma- 
tized with  oil  of  bitter  almonds. 


426  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Almond  Shaving  Cream. — Take  a  few  pounds  of  the  above 
soft  soap,  introduce  it  into  a  marble  mortar,  and  strongly 
triturate  with  a  wooden  pestle.  The  operation  is  finished 
when  the  soap  forms  a  soft  and  homogeneous  paste ;  the  more 
it  is  beaten,  the  finer  it  will  be.  To  perfume  it,  incorporate 
from  IJ  to  2  drachms  of  oil  of  bitter  almonds  per  pound. 

Thus  prepared,  this  soap  forms  an  unctuous  paste  very 
soluble  in  water.  When  it  contains  some  cocoa-nut  oil,  it 
is  yet  softer. 

Hose  Shaving  Cream. — To  give  this  soap  a  slight  rose  color, 
when  pearling  add  one-quarter  to  one-half  a  drachm  of  ver- 
milion per  pound  of  soap,  perfume  with  otto  of  rose ;  it  then 
takes  the  name  of  rose  shaving  cream. 

Ambrosial  Shaving  Cream^  Creme  d^Ambrosie.  —  Perfume 
with  liquid  storax  and  benzoin,  oils  of  bergamot  and  cloves, 
and  color  purple  with  tincture  of  archil. 


Shaving  Cream  by  Boiling. 

In  some  instances,  a  soap  by  boiling  will  prove  more  satis- 
factory, particularly  when  it  is  mixed  and  milled  with  a 
soda  soap  to  form  shaving  tablets.  The  cream  is  rarely  of  so 
white  a  color  as  that  made  by  the  cold  process.  To  proceed, 
take  30  pounds  of  white  grease  to  45  pounds  of  potash-lye 
of  17°  B.,  and  boil  gently  while  stirring,  until  a  paste  is 
formed,  when  boil  more  briskly  until  the  vapors  nearly  cease, 
and  the  soap  forms  into  an  almost  perfect  jelly  when  it  is 
finished,  and  when  cold  it  should  be  almost  neutral. 


I^aples  Soap,  or  Shaving  Cream. 
Take  of  the 


Boiled  soft  soap 

Gum  tragacanth 

Tincture  of  musk 
*'       "  ambergris 
"      *'  balsam  Peru 

Oil  of  geranium 

Color  a  light  brown. 


50  lbs. 
2  ounces. 

2  " 

1  ounce. 

3  ounces. 

2  " 


MISCELLANEOUS  TOILET  AND  MEDICATED  SOAPS.  427 


Soap  Balls  or  Savonettes, 

Often  called  wash  balls,  once  very  much  used,  are  made  of 
any  good  hard  soap  cut  into  squares  and  rounded  in  the 
hand  with  a  brass  tool  until  spherical.  The  mottled  soap 
marbled  with  vermilion  and  ultramarine  is  the  kind  most 
used.  The  transparent  soaps  are  also  formed  into  balls  and 
have  a  good  appearence,  and  are  still  much  in  vogue. 

Glycerine  Cocoa-nut  Oil  Soap. 

Cocoa-nut  oil   50  lbs. 

Tallow   30 

Soda  lye,  380  B   36 

Starch   4 

Soluble  glass   10 

Salt  water   10 

Glycerine,  26°  B   10 

Perfume  with 

Oil  of  mirbane  1  lb. 

"     cassia  •     i  " 

A  handsome  white  translucent  soap. 

We  think  it  is  unnecessary  to  extend  the  list  further,  as 
we  have  more  than  outlined  the  numerous  soaps  in  vogue, 
and  given  examples  that  should  be  amply  sufficient  to  any 
intelligent  manufacturer.  To  give  the  formulas  of  all  the 
different  soaps  of  commerce  would  require  space  that  would 
double  the  size  of  our  volume.  We  must  proceed  to  the 
more  important  subject  of  manipulating  toilet  soaps,  for  in 
the  quality  of  the  work  bestowed  upon  them,  depends  much 
of  their  superiority  and  their  good  appearance. 


428 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


SECTIOiT  XXII. 

MANIPULATION  OF  SOAPS. 

Machinery  and  Appliances,  Perfuming,  Coloring, 
Finishing,  etc. 

For  this  important  portion  of  our  work  we  must  give  many 
particulars  with  descriptions  of  all  the  newest  kinds  of  appa- 
ratus that  have  been  invented  to  aid  in  this  useful  manu- 
facture. In  the  chapters  on  domestic  soaps  we  have  given 
descriptions  of  the  usual  appliances  for  this  fabrication,  which, 
in  the  making  of  the  soaps,  are  equally  applicable  to  toilet 
soaps,  and  a  necessary  part  of  the  plant,  though,  if  toilet  soaps 
only  are  made,  they  need  not  be  of  so  great  a  capacity  or  on 
so  large  a  scale.  It  will  not  be  necessary  here  to  repeat  these 
descriptions.  But  for  toilet  soaps  many  other  and  useful 
machines  are  requisite,  which  we  will  illustrate  and  describe. 

Soap  Caking  Machine. 

When  the  soap  from  the  frames  is  submitted  to  the  slabbing 
and  barring  machine,  it  is  necessary  still  further  to  divide 
it  into  small  cakes  of  a  convenient  size  for  moulding.  For 
this  purpose  the  machine  here  shown  (Fig.  64)  is  very  con- 
venient. The  case  or  box  a,  which  has  a  width  of  about  12 
inches,  and  whose  length  is  dependent  on  the  length  of  the 
soap-bars  which  are  to  be  cut,  serves  for  the  reception  of 
the  bars  b.  The  crank  c  moves  the  bars  of  a  rack  and 
pinion  jack  which  is  supplied  with  a  thumb-screw.  In 
front  of  it  is  affixed  the  cutting-frame  of  wrought  iron, 
which  by  means  of  the  crank/,  moves  several  secure  guides, 
thus,  that  two  girths     winding  up  and  ofl'  around  the  two 


MANIPULATION  OF  SOAPS. 


429 


shafts  h.  Upon  the  frame  e  the  cutting-wire  i  is  placed  across 
the  case  a  about  one  centimetre  below  the  level  of  the  bottom 
of  the  case,  that  one  of  the  ends  is  fastened  to  the  spring  ^, 
while  the  other — after  giving  to  the  wire  its  guide  over  the 


Fig.  64. 


Soap  Caking  Machine. 


two  rolls  I — is  fastened  to  the  pin  m,  which  is  supplied  with 
a  check  appliance.  With  the  frame  e  are  furthermore  con- 
nected, the  round  iron  bar  n  and  the  measuring  board  o, 
which  on  its  upper  part  is  divided  in  fork-shape,  so  that  by 
the  movement  of  the  frame  e  up  and  down,  it  must  needs  also 
make  this  same  motion  with  the  frame  in  the  front  part  of 
the  table  p.  The  front  table  is  likewise  divided,  so  that  the 
forks  of  the  board  may  enter.  The  strict  guidance  of  the 
vertical  motion  of  the  board  is  effected  by  the  guiding 
ledges  q.  The  measure-board  o  is  furthermore  connected 
with  the  screw  r,  which  is  turned  by  means  of  the  crank 
thus  carrying  out  the  horizontal  motion  of  the  measuring 
board. 


430  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

The  work  with  this  machine  is  conducted  as  follows: 
Fill  the  case  a  with  bars  h  and  then  by  turning  the  crank 
s  bring  the  measuring-board  o  the  distance  to  the  cutting- 
wire  z,  that  the  pieces  are  desired  to  measure  in  length. 
Thereupon  turn  by  means  of  the  left  hand,  with  the  crank 
/,  the  cutting-frame  and  with  it  the  'measuring-board  o 
high  up,  80  that  the  cutting-wire  i  is  situated  above  the 
level  of  the  bar  h  w^hich  is  to  be  cut.  Then  turn  by  the 
use  of  the  right  hand,  by  means  of  the  crank  c  and  the  rack 
and  pinion  all  the  bars  h  which  are  in  the  case  a  forward, 
and  under  the  wire  until  they  are  pushed  upon  the  raised 
measuring-board  o.  (In  our  representation  the  apparatus  ap- 
pears in  this  position.)  J^ow,  the  cutting  may  begin,  by 
simply  moving  the  cutting-frame  by  applying  the  crank/ 
downwards,  and  thereby  cutting  all  the  bars  with  the  wire  i. 
Whereas  by  descending  of  the  cutting-frame  e  the  measuring- 
board  likewise  descends,  thus  forming  a  surface  or  one  plane 
with  the  surface  of  the  front  table  ip.  The  removal  of  the 
soap  thus  cut  becomes  very  convenient. 

Fig.  05. 


Cutting  Table. 


As  the  measuring  board  o  can  be  placed  at  every  desirable 
distance  from  the  cutting  wire  i,  the  bars  may  be  cut  by  this 
machine  very  accurately  into  pieces  of  any  desirable  length. 
Such  a  machine  may  be  handled  by  a  mere  lad,  and  with  it, 
ICQ  pounds  of  soap  may  be  cut  within  about  two  minutes 
into  pieces  of  any  desired  length. 


MANIPULATION  OF  SOAPS. 


431 


Cutting  Table. — We  also  illustrate  a  cutting  table,  Fig.  65, 
which  by  some  manufacturers  is  preferred,  in  fact  is  handier 
for  cutting  the  strips  that  are  formed  by  the  plotters,  as  they 
are  too  long  for  the  cutter  previously  described.  A  detailed 
description  is  not  necessary,  as  the  illustration  shows  the 
manner  of  working,  which  is  also  very  rapid.  To  work 
with  this  machine,  the  bars  of  soap  S  S  S  are  laid  upon 
the  table  A  and  cut  by  the  wire  E.  The  gauge-board  F  is 
fastened  by  thumb-screws  G  G  beneath  the  table. 

Hand  Press. — When  these  cakes  are  to  be  moulded  they 
are  previously  placed  upon  racks,  which  is  an  arrangement  of 
latticed  strips  of  wood  either  stationary  or  portable,  and 
similar  to  those  described  elsewhere.    After  they  are  suffi- 


Hand  Soap  Press, 


ciently  dry  it  is  often  necessary  to  give  them  a  form  similar 
to  that  intended  as  a  finish,  which  is  often  done  in  a  hand 
press  in  a  plain  mould.  This  press  is  here  illustrated,  and 
there  are  many  other  similar  ones  made  and  used. 


432  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


King's  Foot  Power  Press. — A  soap  press  worked  by  the  foot 
is  also  used  for  this  purpose,  in  fact  for  general  use;  and  is  a 
much  more  convenient  and  powerful  press,  and  has  been  in 
common  use;  we  illustrate  it  here.  Among  many  similar 
foot  presses  this  is  we  think  the  most  powerful ;  one  blow 
being  usually  sufficient  to  mould  the  largest  size  cake.  It 
is  made  by  W.  H.  King,  of  Philadelphia. 


Fig.  67. 


King's  Foot-Power  Soap  Press. 


Hersey's  Patent  Steam  Press. — For  an  extensive  business  the 
steam  press  made  by  the  Messrs.  Hersey  Brothers,  South 
Boston,  Mass.,  is  the  most  useful  one  we  know  of,  as  a  smart 
workman  can  upon  it  mould  2000  cakes  an  hour. 

The  modus  operandi  of  the  press  is  very  simple,  viz.: — 
A  gentle  pressure  of  the  foot  upon  the  treadle  fills  the 
cylinder  with  steam,  causing  the  die  to  descend  with  light- 
ning rapidity  upon  the  cake  of  soap,  and  the  instantaneous 
return  of  the  lever  raises  it  out  of  the  die-box  ready  for 
removal.    The  blow  given  by  the  steam  soap  press  is  so 


MANIPULATION  OF  SOAPS. 


433 


powerful  that  the  soap  pressed  by  it  looks  better,  and  is  more 
solid  than  when  operated  upon  by  the  old-fashioned  foot 

Fig.  68. 


Hersey's  Patent  Steam  Soap  Press. 


power  press.  The  cost  of  running  it  is  so  trifling  that  the 
required  amount  of  steam  at  twenty  pounds  pressure,  con- 
veyed through  a  one-inch  pipe,  would  not  be  missed  from  a 

28 


434  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


very  small  steam  boiler.  The  entire  press  is  constructed  in 
a  very  substantial  manner.  It  is  ready  for  work  at  short 
notice,  as  it  is  only  necessary  to  connect  it  with  steam  piping 
and  commence  pressing  immediately.  Cakes  of  soap,  vary- 
ing in  weight  from  a  few  ounces  up  to  the  very  largest  sizes, 
are  pressed  with  the  greatest  ease. 

Stripping  of  Soaps. — In  the  manipulation  of  soaps,  the 
stock  soaps  previously  mentioned  have  to  be  cut  into  shav- 


Fig.  69. 


Rutschman's  Stripping  Machine. 


ino:s  or  chips  previous  to  receiving  their  color  and  perfume, 
and  to  being  milled.  For  this  purpose  many  machines  have 
been  invented  and  are  of  very  simple  construction,  but  all  of 
them  are  an  improvement  upon  the  plane,  the  implement 


MANIPULATION  OP  SOAPS. 


435 


formerly  used.  The  latest  and  most  approved  machine  for 
this  purpose  is  that  made  by  the  Messrs.  Rutschman  and 
Brother  of  Philadelphia,  which  is  given  here. 

This  stripper  or  clipper  works  with  great  rapidity.  The 
plate  has  six  knives  which  can  be  regulated  to  cut  the  shavings 
of  any  thinness,  and  can  be  cleaned  with  ease.  In  working 
it  is  only  necessary  to  lay  the  bars  of  soap  in  the  hopper 
and  set  the  machine  running,  and  it  will  strip  several  hun- 
dred pounds  an  hour. 

Soap  Mills. — After  the  soap  has  been  reduced  to  shavings 
by  means  of  the  stripper  or  clipper,  and,  as  it  is  technically 


Fig.  70. 


Rutschman's  Power  Soap  Mill. 


called,  stripped,  these  are  mixed  with  the  requisite  coloring 
(if  to  be  colored),  and  perfume  (if  to  be  perfumed),  and  stirred 
together  in  the  receiving  box,  when  they  are  conveyed  to 
the  mill.   Of  the  many  soap  mills  in  use  none  are  so  powerful 


433 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


or  SO  rapid  as  those  now  made  by  the  Messrs.  Rutschman  of 
Philadelphia,  here  illustrated. 

This  is  the  largest  size,  and  will  mill  2000  pounds  of  soap 
in  a  day.  It  weighs  about  1600  pounds,  and  is  made  so 
strong  and  well  that  it  will  last  many  years  and  do  the  work 
thoroughly. 

By  the  action  of  this  mill  the  soap  is  made  into  a  homo- 
genous mass,  and  the  different  soaps,  the  colors,  and  the  per- 
fumes completely  blended,  by  repeatedly  running  through, 
until  this  object  is  attained. 


Fig.  71. 


Rutschman's  Vertical  Soap  Plotter. 


MANIPULATION  OF  SOAPS. 


437 


:  Plotting.' — When  the  soap  paste  is  smooth  and  shows  no 
grains  or  streaks,  it  is  formed  into  balls  or  cakes  of  the 
required  size;  this  is  called  plotting  or  peloting.  This  opera- 
tion is  now  performed  by  another  machine,  and  one  of  the 
most  useful,  for  in  this  plotter  the  soap  is  pressed  into  a  solid 
substance  with  great  pressure,  insuring  the  cake  when  formed 


Fig.  73. 


Rutschman'a  Hydraulic  Soap-Plotting  Machine. 


4B8 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


against  any  interstices  or  any  liability  to  crack  and  fall  to 
pieces,  when  dry  or  when  wet. 

RutschymrC s  Vertical  Plotting  Machine. — This  valuable  labor- 
saving  machine  (Fig.  71),  made  by  Messrs.  Rutschman  &  Bro., 
Philadelphia,  has  a  capacity  for  100  pounds  of  soap,  and  is 
suitable  for  an  ordinarv  business.  Its  working  is  similar  to 
that  of  the  larger  machine  also  here  shown. 

Hydraulic  Plotting  Machine. — This  new  plotter  (Fig.  72)  is 
also  made  by  the  Messrs.  Rutschman,  who  make  a  specialty 
of  manufacturing  soap  machinery.  It  is  of  great  power,  and 
subjects  the  soap  to  a  pressure  of  3000  to  4000  pounds  to  the 
square  inch.  The  machine  here  illustrated  has  a  capacity  of 
200  pounds  of  soap,  and  can  be  charged  and  discharged  five 
times  a  day,  thus  plotting  1000  pounds  a  day.  It  is  made 
very  substantially,  and  weighs  about  5500  pounds.  Smaller 
plotters  are  made,  but  they  do  not,  of  course,  have  the  same 
power  to  press  the  soap  so  solidly,  and  are,  therefore,  not  so 
suitable. 

Finishing  and  Polishing  the  Soap  Cakes. 

The  cakes  of  soap,  after  they  are  pressed  and  apparently 
ready  for  the  market,  are  often  dried  before  they  can  be 
packed.  In  this  drying  they  may  lose  some  of  their  lustre. 
This  process  is  generally  to  scrape  them  off  and  rub  them 
with  a  woollen  cloth  dipped  in  strong  alcohol,  a  rather 
tedious  process. 

This  somewhat  troublesome  process  has  been  superseded 
according  to  Dupuis  by  another  method,  by  exposing  the 
soap  before  or  after  drying  to  a  stream  of  steam.  The  steam 
can  be  perfumed  with  any  fragrant  odor,  by  passing  it, 
before  reaching  the  soap,  through  a  cloth  which  has  been 
impregnated  with  fragrant  materials.  The  steam  causes  at 
once  a  change  upon  the  surface  of  the  soap  pieces  or  bars, 
and  forms,  according  to  the  fats  applied,  either  a  super-palmi- 
tinate,  or  super-stearic  palmitin-soda  combination.  If  this 
operation  is  carefully  done,  it  closes  up  all  the  pores  and 
uneven  spots,  and  when  dry  forms  a  very  lustrous  cover. 


MANIPULATION  OF  SOAPS. 


439 


which  does  not  suffer  even  under  the  moulding-press.  No 
Other  method  of  polishing  will  give  such  a  beautiful,  even, 
and  lustrous  coating,  as  that  caused  by  steaming.  Further 
advantages  for  this  mode  of  operating  are  economy  in  time, 
hand  labor,  and  prevention  of  all  loss.  Especially  will  it 
preserve  these  soaps  in  damp  magazines,  on  sea-voyages,  and 
in  the  show-windows  of  stores,  where  they  are  exposed  to 
the  rays  of  the  sun. 

Coloring  Toilet  Soaps. 

With  the  many  other  improvements  in  the  manufacture  of 
toilet  soaps,  there  has  been  a  corresponding  advance  in  the 
character  and  nature  of  the  coloring  so  necessary  to  their  at- 
tractive appearance.  While  in  former  times,  ochres,  chromes, 
and  metallic  oxides  of  iron,  as  siennas,  umbers,  etc.,  were 
used  with  many  other  minerals,  the  object  is  now  gained  by 
other  means,  by  substituting  more  soluble  colors  and  such 
as  are  generally  innoxious. 

There  are,  however,  necessary  but  a  few  primitive  colors,  as 
almost  any  shade  can  be  produced  by  a  suitable  blending  of 
them.  Thus  yellow  and  orange  are  made  with  the  naphtha- 
line yellow  or  cadmium  yellow  ;  red  is  still  made  with  ver- 
milion, and  some  shades  with  new  aniline  colors  which  are 
permanent  and  not  affected  by  heat  or  light;  blue  with  ultra- 
marine; green  with  Guinet's  green,  which  is  the  borate  of 
chrome;  browns  are  made  with  caramel,  cutch,  chocolate 
modified  with  red  or  yellow ;  anatoline  is  a  good  yellow  or 
orange  shade.  There  are  also  constantly  occurring  many 
colors  used  in  dyeing,  that  may  find  application  for  soaps, 
which  can,  however,  only  be  known  by  experiment. 

In  coloring  soaps,  it  is  almost  always  most  desirable  to 
color  in  the  process  of  grinding  in  the  mill,  as  it  has  several 
advantages.  It  prevents  the  color  from  being  injured  or 
altered  by  the  heat ;  it  gives  the  full  brilliancy  expected  from 
the  substance,  and  with  much  less  trouble.  Many  of  the 
cheaper  soaps  are  cut  from  the  solid,  and  not  subjected  to  the 
milling  and  plotting  processes.  It  is  then  necessary  to  color 
and  perfume  them  in  the  kettle  or  in  the  frame. 


440 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


The  Perfuming  of  Toilet  Soaps. 


The  perfuming  of  toilet  soaps  may  be  considered  one  of  the 
most  important  branches  of  the  art,  as  the  object  is  to  impart 
a  pleasant  and  at  the  same  time  an  economical  scent.  This 
rather  difficult  matter  is  attained  only  by  good  judgment, 
experience,  and  skill,  all  of  which  require  some  time  to  gain, 
unless  there  be  an  aptitude  in  the  person,  that  is  rarely  met 
with.  It  is,  therefore,  very  proper  and  suitable  that  we 
should  give  some  hints  founded  upon  an  extensive  experience 
in  the  art. 

Many  of  the  essences  or  essential  oils  may  not  be  pleasant 
when  used  alone,  but  when  used  with  others  in  certain  pro- 
portions, may  produce  a  fine  perfume,  and  this  blending  or 
shading  is  where  the  skill  is  needed,  and  w^here  the  attention 
of  the  manufacturer  of  soaps  should  be  given,  for  there  are 
certain  fine  but  expensive  odors  that  are  universally  con- 
sidered pleasant,  but  which  to  use  in  ordinary  soap  would 
enhance  the  cost  too  much;  thus  he  should  have  the  skill  to 
give  an  agreeable  odor  without  making  his  soap  too  costly. 
This  subject  requires  more  attention  than  it  usually  receives, 
and  is  very  important  to  success  in  making  of  toilet  soaps. 

Perfumes  for  Honey  Soap. 
For  each  100  pounds  of  soap — 

I- 

Oil  of  citronella  ....  220  grammes  (7.7  ozs.) 
"  lemon  grass  .  .  .110  "  (3.85  "  ) 
"     cassia  60      "        (2.1    "  ) 


II. 


Oil  of  citronella 
"  thyme 
caraway 


200  grammes  (7  ozs.) 
100      "       (3.5   "  ) 
50      "       (1.75  "  ) 


III. 


Oil  of  lavender 
"  cloves 
' '  rosemary 


thyme 
lemon 


120  grammes  (4.2  ozs.) 
45  (1.58  ) 

65  "  (2.27  "  ) 
50  "  (1.75  "  ) 
65       "        (3.27  "  ) 


MANIPULATION  OF  SOAPS. 


441 


Perfumes  for  Glycerine  Soaps. 


For  each  100  pounds  of  soap — 

I. 

Oil  of  lavender 
"  bergamot 
'*  thyme 
"  cloves 
"  caraway 


Oil  of  rosemary 
"  orange 
"     cassia  . 
"  thyme 
"  myrbane 

Oil  of  bergamot 
' '  lavender 
"  thyme 
"  wintergreen 
"  cassia. 


110  grammes  (3.85  ozs.) 

.8 


80 
40 
30 
20 


05 
.7 


II. 


160  grammes  (5.6  ozs. 
80  "  (2.8  " 
30  "  (1.05  " 
30  "  (1.05  " 
20       "        (0.7  " 


III. 


120  grammes  (4. 
60  "  (2. 
40  "  (1 
30  "  (1 
20       "  (0 


2  ozs. 
1  " 

,4 

05  " 
,7  " 


Perfumes  for  White  Windsor  Soap. 

For  each  100  pounds  of  soap — 

I. 

Oil  of  lavender 
"  cloves. 
"     rosemary  . 
"     caraway     .  . 


II. 


Oil  of  bergamot  . 
"  lavender 
"  cloves 
"  thyme 
"  peppermint. 


210  grammes  (7.35  ozs.) 
40       "        (1.4   "  ) 
80       "        (2.8   "  ) 
60       "        (2.1   "  ) 

120  grammes  (4.2  ozs.  ) 
80  "  (2.8  "  ) 
30  "  (1.05  "  ) 
30  "  (1.05  "  ) 
20       "        (0.7   "  ) 


Perfumes  for  Rose  Soaps. 
To  each  100  pounds  of  unperFumed  soap — 


Oil  of  rose 

"     rose  geranium 

"     cinnamon  (Ceylon) 

"     bergamot  . 

Tincture  of  ambergris  . 


80  grammes  (2.8  ozs. 
60      "  (2.1 
20       "       (0.7  " 
40       "        (1.4  " 
20       »'        (0.7  " 


442 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


II. 


Oil  of  rhodium 
"     rose  geranium 
"     palm  a  rosa  . 
"  cassia. 

Tincture  civet 


80  grammes  (3.8  ozs.) 
80  "  (2.8  "  ) 
60  (2.1    "  ) 

20  (0.7  ) 

20  (0.7  ) 


Perfumes  for  Elder  Flower  Soap. 


For  each  100  pounds  of  soap — 

I. 

Oil  of  lavender 
"  orange 
"  thyme 
"     cassia  . 
'*  wintergreen 


Oil  of  bergamot 
"  lavender 
"  caraway 
"  peppermint 
"  thyme 


II. 


120  grammes  (4.2  ozs.) 


80 
40 
30 
30 


(2.8  "  ) 
(1.4  "  ) 
(1.05  ) 
(1.05  "  ) 


120  grammes  (4.2  ozs.) 
80  "  2.8  "  ) 
60  (2.1  " 

30  "  (1.05  "  ) 
20       ^'        (0.7   "  ) 


Perfume  for  Cashmere  Soap. 


For  each  100  pounds  of  soap 

Oil  of  bergamot  . 
"     rose  geranium 
"     patchouly  . 
"     santal . 
"  valerian 


120  grammes  (4.2  ozs.) 
80  "  (2.8  "  ) 
40  "  (1.4  ) 
30  "  (1.05  ) 
20  (0.7   "  ) 


This  must  suffice  for  hints  to  the  perfuming  of  any  desired 
soap,  and  applies  to  the  soap  that  has  no  perfume,  the  super- 
fine soaps  having  a  portion  of  their  perfume  in  the  previously 
perfumed  greases.  We  have  already  given  the  perfumes 
with  the  formulas  for  the  different  kinds  of  soaps. 


ESSENTIAL  OILS. 


443 


SECTIOIT  XXIII. 

VOLATILE  (ESSENTIAL)    OILS  AND  SOME  OTHER  MATE- 
RIALS, USED  FOR  THE  PERFUMING  OF  SOAPS. 

The  fragrant  volatile  oils  appear  in  commerce  of  very  vary- 
ing qualities,  and  are  frequently  intentionally  adulterated. 
Unfortunately,  the  means  which  we  possess  to  discover  such 
falsifications  are  yet  very  imperfect,  and  the  best  guides  at 
this  juncture  are  always  the  properties  and  characteristics  of 
an  undoubted  genuine  oil,  and  it  is  the  safest  plan  to  pur- 
chase these  very  expensive  materials  from  a  source  which  is 
known  to  be  reliable.  We  intend  by  the  following  to  com- 
municate the  properties  and  the  action  of  a  few  of  these 
mostly  applied  to  this  art.  According  to  the  deviations 
which  an  oil  shows,  from  the  specimen  oil  which  we  have 
on  hand,  it  may  be  judged  with  more  or  less  probability, 
whether  the  same  is  genuine  or  adulterated. 

Oil  of  Valerian. — This  oil  is  produced  by  the  distillation 
of  the  root  of  Valeriana  officinalis  with  water.  Made  of  fresh 
roots  it  is  grassy-green,  from  older  ones  dark-brown.  The  fresh 
oil  is  a  thin  liquid,  becoming  with  age  somewhat  thicker  and 
yellowish-brown  ;  it  possesses  a  very  disagreeable,  penetrating 
valerian  smell,  and  its  strength  and  rankness  increase  with 
age.  The  rectified  oil  has  not  an  unpleasant  odor;  its  taste 
is  camphor-like,  spicy,  and  burning;  it  has  an  acid  reaction 
in  consequence  of  its  contents  of  valerianic  acid;  forms  at 
—29°  C.  (—20.2°  F.)  needle-shaped  crystals,  boils  at  160°  C. 
(320°  F.),  dissolves  easily  in  alcohol.  Its  specific  gravity 
varies  between  0.94  and  0.96. 

Oil  of  Bergamot. — From  the  rind  of  the  Citrus  bergamia, 
belonging  to  the  family  of  Aiirantiacece^funushed  by  pressing. 
It  has  a  specific  gravity  of  from  0.870  to  0.877.    It  is  a  thin 


444  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


liquid  of  yellowish-green  color,  when  old  brownish,  has  an 
agreeable  odor,  spicy  taste,  easily  soluble  in  alcohol,  and  its 
solution  opalizes.  It  is  frequently  adulterated  with  almond 
oil  or  alcohol;  the  first  is  discovered  by  heating  the  oil  in  a 
water-bath,  where  finally  the  non-volatile  oil  of  almonds 
remains.  The  alcohol  is  detected  when  it  is  shaken  with 
red  sandal  wood,  which  with  a  pure  oil  is  not  touched,  but 
in  alcohol  is  colored.  From  the  other  oils  of  the  family 
Aurantiacece  it  difi^ers  by  its  ready  solubility  in  alcohol;  1  part 
of  oil  in  J  part  of  alcohol. 

Oil  of  Bitter  Ahnonds. — This  oil  is  made  in  the  usual 
manner,  by  distilling  the  pulp  made  of  bitter  almonds  with 
water.  The  re-distilled  oil  is  of  a  golden-yellow,  heavier 
than  water,  of  fatty  touch,  and  has  a  penetrating  smell  of 
bitter  almonds  and  a  burning  bitterish  aromatic  taste,  similar 
to  prussic  acid.  It  contains  prussic  acid,  and  acts  as  a  poison. 
The  fresh  rectified  oil  of  bitter  almonds  is  a  colorless,  strong, 
bright-burning,  thickish  liquid,  which  left  exposed  to  the  air 
becomes  yellow  by  absorption  of  carbonic  acid  and  oxygen. 
Its  specific  gravity  =  1.043,  its  boiling  point  180°  C.  (356° 
F.).  It  dissolves  in  30  parts  water,  and  in  every  proportion 
of  alcohol  and  ether.  The  oil  of  bitter  almonds,  for  per- 
fumers and  soap  manufacturers,  is  frequently  adulterated, 
as  is  well  known,  with  the  so-called  mirbane  oil  (essence  de 
mirban,  a  mixture  of  nitro-benzole  and  nitro-tolu  oil),  and 
sometimes  with  enormous  quantities,  even  as  much  as  60 
per  cent.  To  detect  this  adulteration  a  process  has  been 
made  public  by  Bertagnani,  which  is  based  upon  the  easy 
solubility  of  the  benzole-hydrure  (mirbane  oil)  in  an  aqueous 
solution  of  bisulphate  of  ammonia,  in  which  the  mirbane 
oil  easily  dissolves.  The  combination  which  hereby  ensues, 
and  by  a  sufiicient  concentration  of  the  bisulphate  solution 
separates  in  the  form  of  a  crystalline  mass,  is  combined  ac- 
cording to  the  formula  C^gHjgi^ajS^Ojg.  From  it,  by  treatment 
with  a  heated  solution  of  carbonate  of  sodium,  the  benzole- 
hydrure  can  be  again  completely  separated.  Upon  this  action 
R.  Wagner  has  based  a  method  by  means  of  which  the  quan- 
tity of  mirbane  oil  contained  in  an  oil  of  bitter  almonds 


ESSENTIAL  OILS. 


445 


maybe  determined,  which  for  all  technical  purposes  is  am^jly 
sufficient. 

The  genuine  oil  of  bitter  almonds  has  a  specific  gravity  of 
1.040  to  1.044,  while  that  from  aniline  manufactories  (mir- 
bane  oil)  has  a  specific  gravity  of  1.180  to  1.201.  If  a  bitter 
almond  oil  is  suspected  of  an  admixture  with  mirbane 
oil,  it  can  be  tested  in  the  following  manner:  5  cubic  cen- 
timetres (1.35  fiuidraehms)  of  the  oil  to  be  tested  are  ac- 
curately weighed.  If  composed  of  pure  bitter  almond  oil, 
then  it  will  weigh  (at  12.50°  C.  =  54.5°  F.)  5.205  to  5.220 
grammes  (=  80.3  to  80.5  grains),  if  mirbane  oil  only,  then  its 
weight  will  be  5.9  to  6  grammes  (91.03  to  92.6  grains). 
From  the  weight  of  the  above  5  cubic  centimetres  (1.35 
fiuidraehms),  we  can  therefore  approximately  conclude  as  to 
the  quantitative  proportions  of  the  two  liquids  contained  in 
the  sample,  whereby  the  following  table  may  be  used. 

5  c.c.  m.  pure  oil  of  bitter  almonds  (100  %)  weigh  5.20  g. 

5     "     of  a  mixture  of  75  bitter  almond  oil  and  25  mirbane  oil    .  5.30  g. 
5     "         "         "      50         "          "         50         "         .  5.57  g.  , 
5     "         "         "      25         "         "         75         "         .  5.76  g. 
5     "     of  mirbane  oil  5.90  to  6.00  g. 

The  5  cubic  centimetres  oil  are  placed  in  a  mixture  fiask 
with  35  to  40  cubic  centimetres  (1.01  to  1.35  fiuid  ozs.)  of  a 
solution  of  bisulphite  of  sodium  of  at  least  1.225  specific 
gravity  ( =  28°  B.),  and  well  shaken.  The  volume  of  the 
mixture  is  by  adding  water  brought  up  to  50  cubic  centime- 
tres (1.70  fluid  ozs.)  and  placed  in  a  burette,  which  is  left  to 
act  undisturbed,  until  the  mirbane  oil  has  become  separated 
upon  the  specifically  heavier  liquid,  and  appears  as  a  clear 
oil  stratum.  The  quantity  is  read  off  from  the  scale.  If 
for  a  more  exact  measuring  of  the  mirbane  oil  a  pipette, 
divided  into  cubic  centimetres,  is  applied,  then  the  quan- 
tity of  the  addition  to  the  bitter  almond  oil  can  be  deter- 
mined by  1  to  2  per  cent.  In  order  to  lessen  the  consistency 
of  the  oil  and  to  quicken  the  union  of  the  oil  drops,  Wagner 
recommends  shaking  the  entire  liquid  with  5  cubic  centime- 
tres (1.35  fiuidraehms)  of  benzole  or  light  petroleum,  in  order 


446  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


to  ascertain  by  its  increase  of  volume  the  quantity  of  the 
mirbane  oil. 

Oil  of  Lemon  is  procured  by  pressing  or  distilling  the 
rind  of  the  fruit  of  the  Citrus  medica.  In  its  purest  rectified 
condition  it  is  a  colorless,  very  thin  oil.  The  oil  as  it 
appears  in  commerce  is  of  a  pale  yellow,  often  somewhat 
muddy.  It  has  a  very  strong,  agreeable  smell  of  lemons, 
and  a  sharp,  spicy  taste.  Its  specific  gravity  varies  between 
0.848  and  0.860.  In  time  it  will  change,  even  in  sealed 
vessels,  into  a  thick  liquid,  and  will  crystallize.  These 
crystals  are  called  lemon  stereopts,  which  are  very  similar  to 
the  stereopts  of  turpentine  oil.  It  is  sometimes  adulterated 
with  alcohol  and  turpentine.  The  former  is  discovered  by 
means  of  red  sanders ;  the  latter  by  the  change  in  its  aptness 
to  turn  when  exposed  to  an  enhanced  temperature,  since 
lemon  oil  will  withstand  the  influence  of  a  higher  tempera- 
ture much  better  than  oil  of  turpentine.  To  this  end,  the 
turning  capacity  of  the  suspected  oil  is  determined.  Heat 
it  for  one  or  two  hours,  to  about  133°  C.  (271.4°  F.),  and 
determine  again  the  turning  point,  which  now  appears 
altered,  if  the  oil  is  adulterated.  If  the  lemon  oil  contains 
French  turpentine  oil,  the  turning  capacity  increases,  which 
by  the  influence  of  heat  alone  upon  pure  lemon  oil  does  not 
happen. 

Oil  of  Fennel  is  acquired  by  distillation  of  the  bruised 
seeds  of  Anethmn  foeniculum  with  water.  This  oil  is  color- 
less or  yellowish,  and  becomes  darker  with  age;  has  an 
agreeable,  sweetish,  mild,  spicy  smell  and  taste;  its  specific 
gravity  is  0.963  to  1.000;  the  latter  when  the  oil  is  old.  It 
congeals  at  — 10°  C.  (14°  F.),  but  loses  this  property  after 
long  keeping. 

Gaultheria  or  Winter-green  Oil  is  produced  from  Gaultheria 
procumbens^  by  distillation.  All  parts  of  the  plant  seem  to 
contain  this  oil,  though  especially  the  blossoms.  According 
to  Froctor,  the  same  oil  is  obtained  by  distilling  Bentula  lenta, 
a  plant  indigenous  to  North  America.  The  oil  in  commerce 
is  reddish  ;  one  distillation,  however,  suffices  to  discolor  it 
completely;  it  has  both  a  strong  and  a  pleasant  smell,  and  a 


ESSENTIAL  OILS. 


447 


warm  aromatic  taste.  It  is  the  heaviest  of  all  known  vola- 
tile oils  ;  specific  gravity  at  10°  C.  (50°  F.),  about  1.18  ;  it 
begins  to  boil  at  211°  C.  (411.8°  F.),  whence  the  temperature 
gradually  rises  to  220°  C.  (428°  F.)  and  then  becomes  con- 
stant. Winter-green  oil  consists  in  its  main  bulk  of  salicy- 
late of  methyl  oxide,  besides  which  it  also  contains  a  car- 
buretted  hydrogen  gas,  which  is  isomeric  to  the  oil  of  tur- 
pentine.   Its  specific  gravity  is  a  means  for  testing  its  purity. 

Geranium  Oil. — This  oil  is  obtained  by  distilling  with 
water  the  leaves  of  the  rose-geranium,  Geranium  odoratissi- 
mum^  which  is  especially  cultivated  in  Turkey  and  the 
south  of  France.  Geranium  oil  smells  very  much  like  otto 
of  roses,  and  is  for  this  reason  very  frequently  used  for 
adulterating  rose  oil. 

Caraivay-seed  Oil  is  produced  from  the  seed  of  the  com- 
mon caraway  plant,  Carum  carvi,  by  distillation  with  water. 
Caraway-seed  grown  in  colder  regions  or  in  colder  years 
furnishes  more  oil  than  that  which  has  grown  in  warmer 
countries  and  warmer  years.  It  is  in  its  fresh  state  pale-yel- 
low, turns  in  time  dark-yellow  or  brownish,  and  is  a  very 
thin  liquid.  The  statements  as  to  its  specific  gravity  vary  be- 
tween 0.8845  and  0.9745 ;  the  common  specific  gravity  is  0.910 
and  0.925.  The  smell  and  taste  are  purely  like  caraway. 
It  begins  to  boil  at  190°  C.  (374°  F.).  The  ebullition  at 
first  is  quiet,  and  about  the  third  part  of  the  oil  distils  over. 
From  this  point  the  temperature  rises  faster,  while  the  liquid 
at  the  same  time  begins  to  turn  yellow.  Above  200°  C. 
(392°  F.)  the  oil  decomposes,  leaving  a  brownish  resinous 
mass  in  the  retort. 

Oil  of  Jasmin. — This  is  obtained  from  Jasminum  officinale 
and  Jasminum  grayidiflorum.  The  fresh  blossoms  of  these 
two  jasmin  species  may,  on  account  of  their  small  yield  of 
oil,  most  profitably  be  treated  by  enfleurage,  or  simplified 
thus:  Cotton  is  saturated  with  ben  oil,  layers  of  fresh-cut 
jasmin  flowers  are  spread  upon  it,  and  the  whole  exposed,  in 
covered  vessels,  to  the  influence  of  the  heat  of  the  sun.  After 
a  while  the  blossoms  are  removed,  the  cotton  is  spread  over 
with  fresh  flowers,  and  this  is  repeated  until  the  oil  has 


448  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


acquired  a  thorough  jasmin  smell,  when  it  is  separated 
from  the  cotton  by  pressing.  The  oil  is  of  pale  yellow,  and 
possesses  a  pleasant  jasmin  smell.  Good  jasmin  oil  deposits, 
at  0°  C.  (32°  F.),  jasmin  stereopts,  which  crystallize  into 
lustrous  scales,  which  melt  at  12.5°  C.  (54.5°  F.).  It  is  lighter 
than  water,  and  becomes  easily  soluble  in  alcohol,  ether,  and 
oils.  This  applies  to  the  other  perfume  flowers,  as  tuberose, 
orange  flowers,  etc. 

Limette  Oil  is  produced  from  the  fruit  of  Citrus  limetia  vul- 
garis, has  a  flne  and  aromatic  smell,  while  its  taste  is  burn- 
ing, camphor-like.  It  reacts  strongly  acid,  and  has  a  specific 
gravity  of  0.931. 

Oil  of  Lavender. — Of  this  oil,  which  is  yielded  by  the  various 
species  of  an  herb,  the  Lavendula  spica  especially  of  X.  agusii- 
folia  and  L.  vera^  there  are  many  qualities  in  commerce,  ac 
cording  to  whether  the  flowers  only  are  used,  or  the  flowers 
with  the  leaves,  or  merely  the  leaves,  or  whether  the  entire 
plant  is  subjected  to  distillation  in  water.  The  finest  grade 
is  that  which  is  made  of  the  flowers  only.  The  oil  is  colored 
greenish-yellow,  but  by  rectifying,  it  becomes  colorless, 
though  by  age  it  turns  dark.  It  is  a  thin  liquid,  but  be- 
comes thicker  with  time  or  when  exposed  to  the  air.  Its 
specific  gravity  fluctuates  between  0.897  and  0.936.  The 
best  kind  has  a  fine  lavender  smell,  the  inferior  sorts  have  a 
smell  like  camphor  or  turpentine. 

Oil  of  Cloves. — In  the  home  of  the  cloves,  on  the  Isles  of 
the  Moluccas,  or  Spice  Islands,  Cayenne,  etc.,  there  are  known 
three  varieties  of  the  clove  tree,  viz.:  Cariophyllas  aromati- 
ciis^i.  e,,  with  red,  blood-red,  and  white  fruits;  the  latter 
contain  the  most  oil.  The  oil  is  obtained  from  the  unde- 
veloped blossoms,  but  frequeiitly  merely  from  the  stems,  the 
so-called  clove-wood,  by  distillation. 

In  its  fresh  state  this  oil  is  light-yellow,  afterwards  yel- 
low to  light  brownish-yellow.  It  is  a  thick  liquid,  and 
reddens  litmus  weakly,  has  a  sharp  burning  taste,  a  specific 
gravity  of  1.031  to  1.061;  it  is  but  little  soluble  in  water, 
but  dissolves  in  alcohol,  ether,  concentrated  acetic  acid,  and 
in  the  fat  oils;  begins  to  boil  at  100°  C.  (212°  F.),  and  is  at 


ESSENTIAL  OILS. 


449 


—18°  to  —20°  C.  (—0.4'=^  to  —4°  F.)  still  liquid.  A  common 
falsification  is  the  mixture  with  oil  of  almonds,  with  castor 
oil  and  the  alcoholic  extraction  of  the  cloves,  or  for  pro- 
ducing the  density  of  the  fluid  it  is  mixed  with  colophony. 
As  soon  as  these  admixtures  exceed  the  oil  no  longer  sinks 
in  water.  A  genuine  oil  of  cloves  retains  its  entire  clear- 
ness when  dropped  into  water,  unites  easily  at  the  bottom 
of  the  vessel,  while  an  adulterated  article  discolors  in  its  single 
drops,  and  these  cover  themselves  with  a  whitish  coating 
and  do  not  reunite  easily.  The  presence  of  alcohol  is  discern- 
ible by  shaking  the  oil  with  water,  when  after  clearing  it 
proves  a  thicker  liquid. 

Neroli  or  Orange-Flower  Oil. — This  oil,  obtained  by  dis- 
tillation of  the  orange  blossoms,  Citrus  aurantium^  with 
water,  is  noted  for  its  fine  and  fragrant  smell,  and  is  distin- 
guished over  all  the  other  oils  of  the  family  Aurantiacece  in 
such  a  manner  that  a  falsification  of  it  seems  scarcely  possible. 
It  differs  moreover  in  its  action  with  nitric  acid,  by  which  it 
acquires  a  dark  red-brown  color,  while  the  other  oils  of  the 
same  family  of  plants  are  much  less  colored,  some  only 
slightly  shaded. 

Oilof  Patchouly. — This  oil  is  prepared  by  distillation  of  the 
herb  patchouly  {Pogostomen  Patchouli^  Lindley,  Plectantrus 
crassifoUus,  Burnett),  a  plant  which  grows  in  China  and  the 
East  Indies.  Its  smell  exceeds  that  of  all  other  plants  in 
intensity.  It  is  a  thick  liquid  of  a  brown  color,  and  boils 
at  280°  C.  (586^  F.).  The  adulterations  are  usually  oils  of 
cubebs  and  santal.  The  oil  made  in  its  native  place  is  the 
best. 

Oil  of  Portugal. — The  oil  of  bitter  orange  peel,  or  Portugal 
oil,  is  prepared  by  pressing  or  distilling  the  outer  skin  of  the 
bitter  orange  fruit.  It  is  yellowish,  its  smell  similar  to  that 
of  bergamot  oil;  specific  gravity  =  0.819  to  0.9;  it  boils  at 
180°  C.  (356°  F.).  The  adulterations  are  similar  to  those  of 
the  oils  of  lemon  and  bergamot. 

Attar  of  Poses,  Oil  of  Poses. — This  precious  oil  is  obtained 
from  various  species  of  roses,  from  Posa  moschata,  R.  centi- 
folia.,  Posa  sempervirens,  P,  damascenay  and  others.    In  com- 

29 


450  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


merce  two  kinds  of  rose  oils  are  known,  the  one  is  made  in 
the  East  Indies  from  Rosa  moschata  (India  rose-oil),  the  other 
in  the  Levant  and  Tunis  (Levantic)  of  Itosa  sempervirens. 
The  method  of  producing  rose  oil  is  not  everywhere  the  same. 
In  the  East  Indies  the  plucked  rose  leaves  are  poured  over 
with  spring  water  and  exposed  to  the  sun ;  after  the  lapse  of 
a  few  days  yellow  oily  drops  float  on  the  surface,  which  are 
absorbed  by  a  little  cotton  tied  to  a  rod,  and  pressed  out. 
In  other  places  distillation  is  employed,  the  same  water  is 
distilled  several  times  over,  with  a  renewed  supply  of  rose 
leaves.  The  oil  of  roses  from  Cashmere  is  acknowledged  to 
be  the  most  excellent.  There  they  distil  the  same  water 
over  fresh  roses,  twice,  permitting  it  to  stand  in  open  vessels, 
and  at  nights  the  latter  are  placed  in  cold  water.  The  rose- 
oil  thus  separates  in  the  water  in  small  drops,  which  are 
carefully  taken  off.  The  pure  oil  when  cold  is  in  a  semi-solid 
state,  and  does  not  entirely  liquefy  at  100^  C.  (212°  F.). 
The  genuine  rose-oil  is  but  little  yellowish  in  color,  that  of 
Macedonia  generally  somewhat  darker.  It  has  a  strong, 
penetrating  smell  of  roses,  which,  however,  is  only  agreeable 
as  long  as  it  is  faint,  otherwise  it  causes  headache;  its  taste 
is  mild,  and  a  little  sweetish.  It  congeals  at  a  few  degrees 
below  0°  C.  (32°  F.)  to  an  almost  colorless  translucent,  lustrous 
leafy  mass,  which  turns  perfectly  liquid  only  at  28°  to  30° 
C.  (82.4°  to  86°  F.).    It  does  not  redden  litmus  paper. 

On  account  of  its  high  price,  rose-oil  is  exposed  to  many 
adulterations,  especially  to  the  mixing  with  other  volatile 
oils,  in  which  spermaceti  is  dissolved,  in  order  to  cause  it  to 
congeal  like  the  genuine  rose-oil.  Such  falsification  is 
detected  in  this  wise,  because  genuine  rose-oil  when  melted 
and  slowly  cooled  off  crystallizes  in  thin  translucent  scales, 
which  when  held  up  against  the  light  iridesce  beautifully; 
while  on  the  other  hand  an  oil  mixed  with  spermaceti,  by 
congealing  becomes  almost  dense,  on  account  of  the  separa- 
tion of  the  line  crystalline  needles. 

Most  frequently  rose-oil  is  now-a-days  adulterated  with  the 
volatile  oils  of  the  various  species  of  Pelargonium  odoratissi- 
miim,  P.  capitum^  and  P.  roseum,  i.  e.,  geranium  oils;  less 


ESSENTIAL  OILS. 


451 


often  the  falsification  happens  with  rosewood  oil,  since  it  is 
almost  as  expensive  as  rose-oil  itself.  Whether  we  are  hand- 
ling a  genuine  rose-oil  or  a  spurious  article  can  be  ascer- 
tained by  mixing  a  few  drops  of  concentrated  sulphuric  acid 
with  the  sample,  when  in  the  genuine  article  the  fragrance 
remains  unaltered,  but  in  a  mixture  of  Pelargonium-oil  a 
very  disagreeable  strong  smell  develops. 

Oil  of  Sassafras  is  the  product  of  the  distillation  of  the 
root  of  the  sassafras  tree,  Laurus  sassafras^  a  native  of  the 
United  States.  In  its  fresh  state  the  oil  is  colorless  or  pale 
yellowish,  in  time  it  becomes  dark  reddish-brown.  It  has  an 
agreeable  fragrance  and  a  sharp  spicy  taste.  After  keeping 
it  for  a  longer  period  it  separates  a  large  quantity  of  stearopts, 
which  crystallize  in  translucent,  colorless,  rhombic  quadri- 
lateral, or  irregular  hexagon  prisms,  with  double  planed 
points.  The  specific  gravity  varies  between  1.07  and  1.09. 
It  reddens  litmus  paper,  and  by  shaking  up  with  water  may 
be  separated  into  two  oils,  of  which  the  one  is  lighter,  the 
other  heavier  than  water.  The  usual  adulteration  is  with 
oil  of  turpentine. 

Oil  of  Marjoram  (Spanish  hops). — The  oil  is  obtained  by 
distilling  the  flowering  herb  of  Origanum  Majoi^ana  of  the 
family  of  labiate  flowers.  In  its  fresh  state  the  oil  is  a 
light  straw-color,  but  in  time  turns  to  a  red-brown.  It  is 
a  thin  liquid  of  0.946  specific  gravity,  and  does  not  redden 
litmus  paper,  has  a  penetrating  spicy  smell,  and  a  sharp 
burnino;  taste. 

Oil  of  Thyme. — To  produce  this  oil  from  Thymus  vulgaris 
by  distillation  with  water,  it  is  best  to  use  the  fresh  herb. 
The  oil  is  a  thin  liquid,  which  by  age  thickens,  and  when  it 
is  unadulterated  it  precipitates  stearopts  if  kept  for  a  longer 
period.  In  the  rectified  state  it  is  colorless,  turns  gra- 
dually yellow  and  brownish-red.  It  has  the  strong  and 
pleasant  smell  of  the  plant,  and  a  camphor-like,  cooling, 
biting  taste.  The  fresh  oil  is  neutral,  the  old  brownish 
colored  article  very  acid.  Its  specific  gravity  is  0.886  to 
0.891. 


452  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

Oil  of  Vitivert. — The  oil  of  vitivert  is  obtained  from  the 
root  of  vitivert  by  distillation.  This  is  the  root  of  an  Indian 
grass  species  of  Anatherum  medicatum.  Vitivert  oil  smells 
very  aromatic,  boils  at  286°  C.  (546.8°  F.),  and  has  much  simi- 
larity with  the  santal  wood  oil. 

Cassia  Oil. — This  oil  is  manufactured  in  its  native  country, 
by  distilling  the  bark  of  Cinnamormim  aromaticimi.  The  fresh 
oil  is  light,  turns  witli  age  to  a  darker  yellow.  Its  fragrance 
is  pleasant  and  cinnamon-like;  but  less  refined  than  the 
genuine  cinnamon  oil;  nor  is  its  taste  as  sweet  as  that  of  the 
genuine  article,  but  sharper.  Specific  gravity  =  1.060;  at 
27.5°  C.  (81.5^  F.),  firm  crystals  separate,  which,  however, 
in  the  warmth  again  become  liquid.  The  oil  has  an  acid 
reaction. 

Oil  of  Rosemary  distilled  from  the  fresh  beans  of  the  Hos- 
marinus  officinalis  is  colorless,  with  an  agreeable  camphor- 
like smell.  Its  specific  gravity  is  0.911,  it  boils  at  185^  C. 
(365°  F.),  and  its  composition  is  C^jHggOj.  If  kept  it  deposits 
stearopts  analogous  to  camphor.  The  adulterations  are  usually 
with  oil  of  turpentine,  which  is  not  easily  separated  or  de- 
tected. 

Oil  of  Canada  Snakeroot^  from  the  root  of  the  Asarum 
Canadense,  is  of  a  very  agreeable  spicy  odor  now  much  in 
vogue  for  essences,  and  blends  so  well  with  other  oils  that  it 
might  have  a  useful  application  for  fine  soaps. 

Oil  of  Pimento  is  prepared  from  the  berries  of  the  allspice, 
but,  as  they  do  not  yield  much  oil,  I  to  4  per  cent.,  the  cost 
is  higher  than  the  other  useful  spice  oils,  yet  it  can  be  often 
applied  to  shade  mixtures  of  other  oils. 

Oil  of  Nutmegs. — Xutmegs  yield  two  oils,  a  limpid  oil  by 
distillation  with  water,  and  a  concrete  oil  by  expression. 
The  former  is  used  in  soap  in  combination  with  other  essen- 
tial oils.  The  concrete,  or  oil  of  mace,  is  also  used  in  soap, 
but  combined  with  the  grease  before  saponification. 

Oil  of  Cinnamon  (Ceylon),  obtained  by  distillation  of  the 
bark  of  Cinnamomum  venim,  with  water,  on  the  Island  of 
Ceylon.  In  its  chemical  aspect,  it  is  similar  to  the  cassia. 
The  fresh  distilled  oil,  rectified  by  exclusion  of  air  or  oxygen, 


ESSENTIAL  OILS,  ETC. 


453 


is  a  thin  liquid,  of  a  light  yellow  color,  but  it  soon  thickens 
and  also  acquires  a  darker  color.  Smell  and  taste  are  almost 
identical  with  that  of  the  cassia  oil,  but  finer.  Its  specific 
gravity  ranges  between  1.01  and  1.10;  it  remains  liquid  at 
—25°  C.  (—13°  F.). 

Ambergris  is  a  product  of  the  diseased  liver  of  the  cachelot 
or  spermaceti  whale.  It  floats  upon  the  surface  of  the  sea, 
and  is  gathered  on  the  coasts  of  Coromandel,  Japan,  the 
Moluccas,  and  Madagascar.  The  color  of  ambergris  is 
(grayish-white)  black,  and  yellow  marbled;  of  strong  smell, 
but  not  unpleasant,  its  taste  is  mild  and  fatty,  and  melts  at 
60°  C.  (140°  F.).  It  dissolves  easily  in  absolute  alcohol, 
ether,  and  also  in  fat  and  volatile  oils,  contains  85  per  cent, 
amber  fat,  which  cannot  be  saponified. 

Musk  or  Bisam, — Musk  originates  from  a  roe-like  animal, 
the  Thibet  musk,  Moschus  moschifera.  The  musk  is  found  in 
a  separate  bag  adjacent  to  the  genital  parts  of  the  male, 
never  in  the  female,  and  forms  in  its  fresh  state  an  ointment- 
like reddish-brown  substance  of  a  specific,  penetrating,  en- 
during odor,  and  has  a  bitter,  oftensive,  spicy,  salty  taste. 
In  commerce  two  kinds  of  musk  are  known,  to  wit,  Inugi- 
nic  and  Carbadinic  musk.  The  first,  by  far  the  better,  pos- 
sesses alone  that  fine  odor,  while  the  Carbadinic  musk  often 
has  a  sharp  ammonia-like  smell.  In  commerce  musk  appears 
in  the  form  of  the  natural  bags  of  the  animal,  and  this  is 
a  special  sign  of  genuineness  and  unadulterated  state, 
when  these  bags  are  entirely  intact,  they  are  often  cut  open 
on  the  sides  and  filled  with  other  substances  and  finely 
sewed  up  again.  The  contents  of  such  a  bag  appear  as  a 
moist,  grainy,  mass  of  dark  brown  color,  but  little  inter- 
spersed by  small  membranes.  The  Carbadine  musk  consists 
frequently  almost  entirely  of  skinny  membranes  with  but 
little  grainy  musk,  of  a  less  dark  color,  even  sometimes  light 
brown.  In  purchasing  a  bag  attention  should  also  be  paid, 
that  through  the  natural  opening  of  such  a  bag,  no  other 
substances,  as  shot,  fine  quartz  grains,  etc.,  have  been  in- 
serted, in  order  to  enhance  its  weight. 


454  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Peruvian  Balsam, — According  to  the  report  made  by  Dr. 
l)oret,  who  obtained  his  information  at  the  native  place,  the 
Peruvian  balsam  originates  solely  from  Myrospermumpereira. 
To  obtain  it,  the  bark  of  the  tree  is  beaten  in  four  different 
places,  so  that  it  peels  off  from  the  trunk  of  the  tree.  A  few 
days  after,  these  places  are  heated  with  burning  torches, 
taking  the  bark  away  and  placing  cloths  upon  the  stripped 
places,  which  absorb  the  oozed-out  balsam.  These  cloths 
are  boiled  out  in  a  vessel  with  water,  until  they  appear  en- 
tirely free  from  balsam.  The  water  cooling  off,  the  bal- 
sam settles  upon  the  bottom.  The  balsam  obtained  thus, 
forms  a  dark  brown,  syrup-like,  opaque  liquid,  of  a  very  pleas- 
ant vanilla  or  benzoin-like  fragrance,  and  aromatic,  lasting 
taste.  Sometimes  it  is  adulterated  by  mixing  castor  oil  with 
it.  In  order  to  detect  this,  distil  10  grammes  (0.35  oz.), 
shaking  the  distillate,  which  consists  of  two  layers,  in  baryta 
w^ater,  taking  off  the  oil-layer  floating  upon  it,  by  means  of 
a  pipette,  and  shaking  it  with  a  concentrated  solution  of 
bisulphide  of  soda.  If  the  so-treated  balsam  contains  some 
castor  oil,  the  shaken  balsam  congeals  forthwith  into  a  crys- 
talline mass. 

Civet. — By  this  name  we  designate  an  animal  secretion, 
which  orignates  from  Viverra  zibetha^  the  Asiatic,  and  Viverra 
civetta,  the  African  civet.  It  separates  in  these  animals 
from  particular  glands  into  a  sort  of  pocket,  which  is 
situated  between  the  anus  and  the  genital  organs,  and 
opening  outside.  The  wild  animal  squirts  this  mass  from 
time  to  time  spontaneously;  from  the  captured  animal  it  is 
taken  with  a  spoon.  Civet  forms  a  smeary,  soft,  at  first 
white,  after  a  while  brownish  mass,  becoming  in  time  more 
consistent.  It  has  a  peculiar  musk  or  amber-like  fragrance, 
and  a  disagreeable,  bitter,  irritating  taste.  It  melts  when 
heated,  puffs  up,.takes  fire,  and  burns  with  a  bright  flame. 

Tincture  of  Civet. 

Civet   2  ounces. 

Orris  root  (ground)   4  " 

Alcohol   8  pints. 


ESSENTIAL  OILS,  ETC.  455 

Triturate  the  civet  with  the  orris  in  a  mortar,  adding 
the  alcohol  by  degrees.  * 

Tincture  of  Ambergris. 

Ambergris  (gray)   2  ounces. 

Loaf  sugar   4  " 

Alcohol   8  pints. 

Tincture  of  Mush. 

Musk  (the  best)  2  ounces. 

Sugar  4  " 


Alcohol  8  pints. 

These  tinctures  should  be  kept  in  a  warm  place,  occasion- 
ally stirring  for  a  month  to  properly  extract  the  odors, 
which  being  of  animal  origin  are  difficult  of  solution. 

These  perfumes  are  those  best  known;  there  are,  however, 
many  other  oils  and  substances  used  in  perfuming  soaps,  but 
they  are  of  minor  importance. 


PART  II. 

THE  MANUFACTURE  OF  CANDLES. 


SECTION  I. 

INTRODUCTION,  INCLUDING  THE  THEORY  OF  FLAME. 

Of  all  means  of  artificial  illumination  candles  are  perhaps 
the  most  convenient,  and  the  bodies  from  which  they  can  be 
made,  though  not  very  numerous,  are  such  as  are  generally 
easily  obtained  and  many  of  them  cheap  in  cost.  Thus  tal- 
low, tard,  paraffine,  spermaceti,  wax,  palm  and  cocoa-nut 
oil  comprise  nearly  all  the  materials  used  for  this  purpose. 
A  candle  consists  of  one  or  more  of  these  solid  illuminating 
materials  in  the  well-known  cylindrical  shape  and  provided 
in  the  direction  of  its  longitudinal  axis  with  a  cotton  wick, 
the  thickness  and  plaiting  of  which  are  arranged  in  proper 
relation  to  the  diameter  of  the  candle. 

It  is  difficult  to  trace  from  history  the  first  introduction 
of  the  candle.  Lamps  are  frequently  spoken  of  in  ancient 
history,  and  the  Romans  possessed  other  means  of  illumina- 
tion supposed  to  be  a  kind  of  reed  whose  pith  was  saturated 
with  grease  or  wax  with  a  wick  made  of  a  film  of  flax  simi- 
larly saturated.  Wax  was  no  doubt  the  first  material  used 
for  this  purpose,  and  Venice  seems  to  have  been  the  first  to 
have  made  them  in  sufficient  quantity  to  be  called  an  art, 
though  they  had  been  made  for  church  purposes  a  long  while 
before. 

In  the  17th  century  the  art  was  introduced  into  Paris,  and 
as  wax  was  not  abundant  they  were  very  costly,  and  their 
use  was  confined  to  princely  courts  or  wealthy  churches. 


458  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Tallow  candles  were  made  at  a  very  early  date,  though  not 
as  an  established  industry,  for  up  to  the  17th  century  oil 
was  the  principal  means  of  light ;  candles  were  too  scarce 
and  high  priced  for  use  among  the  masses,  and  they  do  not 
seem  to  have  been  in  general  use  until  the  middle  of  the  last 
century,  nor  was  there  any  important  improvement  in  the 
art  from  the  first  crude  methods  of  dipping  except  that  they 
were  about  that  period  moulded  in  metal  moulds.  Indeed 
up  to  our  own  century  very  little  improvement  can  be  traced, 
nor  did  they  receive  their  due  importance  or  approach  their 
present  perfection  until  the  discovery  of  the  elements  of  the 
fatty  bodies  and  their  decomposition  into  the  fatty  acids, 
stearic  and  palmitic. 

This  we  owe  to  the  researches  of  Chevreul,  Braconnet, 
Maujot,  and  others.  Gay  Lussac  witb  Chevreul  received  a 
patent  in  1825  for  making  stearic  acid  candles  and  convert- 
ing the  oleic  acid  produced  in  the  manufacture  into  soap, 
nor  was  it  until  1834  that  they  had  succeeded  in  making 
candles  that  were  considered  faultless.  Spermaceti  candles 
had  then  been  in  use  for  about  fifty  years,  but  they  were 
costly  and  were  not  in  general  use. 

When  in  1830  paraffine  was  discovered,  candles  were 
further  improved  by  the  addition  of  this  valuable  substance 
to  the  stearic  acid  to  prevent  their  crystallization,  or  the 
stearic  acid  was  combined  with  the  paraffine  to  improve 
them  and  prevent  their  softening  and  bending  in  a  warm 
atmosphere. 

Candles  of  tallow  or  wax  were  first  made  by  dipping ;  the 
latter  were  sometimes  made  by  drawing  and  rolling,  a  mode 
still  in  vogue.  The  moulding  of  candles  is  of  quite  recent 
date,  for,  though  they  were  moulded  over  a  hundred  years 
ago,  they  were  not  made  systematically  until  1820,  and  now 
owing  to  the  many  improvements  in  the  materials  and  in  the 
appliances  for  moulding  with  great  facility  and  rapidity,  in 
fact  such  has  been  the  improvement  in  every  branch  of  this 
art  that  it  may  be  said  to  have  reached  perfection. 

Beef  and  mutton  tallow  are  the  chief  animal  fats  used  for 
candles;  they  consist  mostly  of  stearin,  palmitin,  and  olein, 


INTRODUCTION,  INCLUDING  THE  THEORY  OF  FLAME.  459 

stearin  being  the  larger  part,  varying  with  the  age  and  kind 
of  food.  Beef  tallow  has  a  yellowish  color,  is  hard  and 
brittle,  melts  at  about  38^  C.  (100.4°  F.),  is  insoluble  in  water, 
but  dissolves  in  40  parts  of  heated  alcohol.  Mutton  tallow 
when  fresh  has  but  little  color  or  odor,  soon  becoming  rancid 
when  exposed  to  the  air,  is  less  soluble  in  alcohol  than  beef 
tallow,  and  its  melting  point  is  about  the  same. 

Hog's  lard,  much  nsed  in  this  country  for  making  candles, 
having  less  stearin  than  olein,  the  latter  has  to  be  separated 
before  it  can  be  used  for  this  purpose.  Lard  of  good  quality 
(and  the  quality  varies  very  much)  is  a  white  oleagineous 
substance  melting  at  about  27°  C.  (80.6°  F.),  and  is  very 
largely  used  for  culinary  purposes. 

Stearin  and  stearic  acid  are  the  base  of  most  of  the  candles 
now  in  use.  The  term  stearin  does  not  express  the  true  cha- 
racter of  this  substance — it  being  stearic  acid — but  as  it  is 
the  one  accepted  by  commerce  it  may  be  proper  to  retain  it. 
This  valuable  substance,  the  result  of  certain  chemical  pro- 
cesses, is  now  manufactured  in  nearly  all  parts  of  the  world, 
and  if  properly  made  is  a  beautiful  hard  pearl-white  solid 
which  can  be  made  from  almost  any  description  of  fatty 
matter.  Though  known  and  used  for  a  long  while  before,  it 
was  not  till  1831  that  De  Milly  overcame  all  previous  diffi- 
culties and  made  stearin  on  a  larger  scale,  establishing  the 
industry  upon  principles  which  have  been  retained  almost 
unaltered.  Some  of  the  processes  have  been  materially 
changed  and  principally  by  the  same  chemist. 

From  palm  oil  and  cocoa-nut  oil  and  other  vegetable  oils 
and  greases  candles  are  now  made,  the  solid  portions  of  these 
oils  being  extracted  in  a  similar  manner  to  that  in  vogue 
for  the  other  grease  bodies  already  mentioned,  with  some 
modifications  suitable  to  their  nature.  Thus  it  will  be  seen 
that  the  making  of  candles  is  now  a  scientific  chemical 
industry  of  great  importance,  instead  of  the  simple  art  it 
once  was,  when  it  was  confined  to  the  making  of  candles  of 
tallow  by  dipping  or  moulding. 

To  illustrate  the  great  importance  of  the  stearic  acid 


460 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


industry,  it  is  interesting  to  know  that  France  alone  pro- 
duces at  least  60,000,000  pounds,  the  remainder  of  Europe 
250,000,000  pounds ;  America  about  30,000,000  pounds.  The 
great  candle  factor}^  of  Price  &  Co.,  of  London  and  Liver- 
pool, with  a  capital  of  $5,000,000,  makes  many  kinds  of  can- 
dles, principally  those  called  composition  candles,  whose  base 
is  mostly  extracted  from  palm  oil  and  cocoa-nut  oil.  These 
candles  are  used  by  nearly  all  classes  in  England.  France, 
however,  may  be  considered  the  largest  consumer  of  candles, 
and  generally  of  the  better  kinds,  the  trade  there  demanding 
hard  white  candles  which  are  consumed  by  all  families  and 
hotels ;  in  fact  that  country  may  be  said  to  excel  in  the  art 
of  manufacturing  candles.  France  may  also  take  a  just  pride 
in  having  given  to  the  world  such  names  as  Chevreul  and 
de  Milly,  who  go  side  by  fiide  in  the  advancement  of  this 
industry,  the  first  by  his  chemical  researches,  the  latter  by 
his  ingenious  devices  in  the  accomplishment  of  great  practi- 
cal results,  a  pride  equal  to  that  of  giving  to  the  world  Le- 
blanc,  who  first  made  artificial  soda  from  culinary  salt,  these 
arts  having  been  of  the  greatest  importance  to  civilized  life 
in  giving  cheap  light  and  cheap  cleanliness. 

The  principles  upon  which  artificial  light  is  formed  from 
the  flame  of  a  candle  are  simple,  as  it  is  only  such  solid  or 
fluid  bodies  as  become  either  volatilized  or  decomposed  into 
gaseous  matter  at  a  temperature  below  that  required  for 
their  combustion  as  can  burn  only  in  the  shape  of  gas.  The 
ensuing  light  is  what  we  call  flame.  The  well-known  shape 
of  flame  is  due  to  the  pressure  of  the  ambient  air,  because 
the  latter  becoming  heated  and  rendered  specifically  lighter 
ascends.  When  the  illuminating  material,  consisting  either 
of  tallow,  stearin,  parafiine  oil,  or  petroleum,  is  sucked  up- 
wards in  the  interstices  of  the  wick  acting  as  capillary  tubes, 
and  in  the  immediate  neighborhood  of  the  flame,  these  sub- 
stances are  consumed  into  gases  and  vapors  the  nature  of 
which  agrees  with  that  of  purified  illuminating  gas. 

In  every  candle  flame  four  distinct  parts  can  be  distin- 
guished: a  (Fig.  73),  a  non-lighting  dark  nucleus;  6,  the 


INTRODUCTION,  INCLUDING  THE  THEORY  OF  FLAME.  461 


mantle,  which  is  the  real  lightino;,  yellowish-white  cover, 
enveloping  it  towards  the  point  above;  the  mantle  which 
surrounds  it  towards  the  base,  and  is  of  a  pretty  azure  blue ; 
d,  the  so-called  veil,  which  envelops  the  entire  flame  sub- 
stance, and  is  of  very  weak  lighting  power,  and  hardly  visi- 
ble. The  dark  nucleus  a  consists  of  the 
gaseous  and  vapory  products  of  decom-  ^'"^ 
position,  by  the  absorption  of  the  liglit- 
ing  material  of  the  wick  c\  6  is  the 
sphere  of  the  partial  combustion  and 
decomposition  of  the  carburetted  hydro- 
gen into  bi-hydroguret  of  carbon,  or 
hydrogen  gas  and  carbon.  Upon  its 
inner  side,  where  it  borders  on  the  dark 
nucleus,  the  lighting  envelop  is  reduc- 
ino^;  towards  the  outside,  where  it  bor- 
ders  on  the  veil,  it  is  oxidizing.  At 
this  place,  the  rejected  carbon,  which 
always  burns  sooner  than  the  hydrogen, 
enters  through  the  veil,  and  there  com- 
bines with  the  oxygen,  forming  carbonic 
oxide.  In  the  veil,  which  surrounds 
the  body  of  the  flame  on  all  sides,  the 
complete  combustion  takes  place ;  that 
is,  carbonic  oxide  and  hydrogen  burn  to 
carbonic  acid  and  water.  Since  in  the 
veil  only  gases  and  no  solid  bodies  are  burning,  its  power 
of  lighting  is  lessened  ;  but  in  lieu  thereof  it  is  the  hottest 
part  of  the  flame,  since  in  it  alone  the  combustion  of  the 
hydrogen  takes  place.  The  veil  envelops  the  entire  surface 
of  the  flame  body,  but  in  various  shades  of  color;  because 
the  carbonic  oxide  burns  at  a  low  degree  of  temperature 
with  a  blue  flame,  and  when  brought  to  a  high  temperature 
it  burns  w^ith  a  yellowish-red  flame.  Hence  the  yellowish- 
red  of  the  veil  at  the  upper  part,  the  azure  blue  at  the 
base. 

It  has  been  customary  to  adduce  that  the  luminosity  of 


462  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


the  flame  is  due  to  the  eliminated  particles  of  carbon  ;  but 
how  could  a  flame  be  so  transparent  as  it  really  is,  were  it 
filled  with  solid  particles  of  carbon  ?  Yet  it  is  possible  that 
this  elimination  ma}'  take  place  in  the  decomposition  of  the 
hydro-carbons. 


MATERIALS  FOR  CANDLES. 


463 


SECTIOIT  11. 

THE  MATERIALS  FOR  CANDLES,  WITH  THEIR 
PREPARATION. 

The  preparation  of  taUoiu  to  make  it  suitable  for  candles  is 
a  comparatively  simple  matter,  and  is  done  in  various  ways, 
but  which  mode  is  the  most  desirable  depends  upon  the 
means  at  hand,  the  quantity  w^orked,  and  other  causes.  In 
small  factories  rendering  by  the  open  fire  is  usually  em- 
ployed. In  large  establishments  tallow  is  rendered  by  means 
of  steam  in  covered  vats  or  kettles,  aided  by  sulphuric  acid, 
caustic  alkalies  or  currents  of  air  in  apparatus  similar  to  that 
of  Vohl,  shown  in  Fig.  1,  page  85,  with  suitable  attachments 
for  burning  the  offensive  gases  arising  from  the  processes.  By 
the  first  mode  the  greaves  or  cracklings  can  be  saved  and 
utilized  in  feeding  swine,  while  the  residuum  from  the  acid 
or  alkali  process  can  only  be  used  as  a  fertilizer. 

At  the  present  time  tallow  in  a  more  or  less  pure  state  is 
an  article  of  commerce,  so  that  few  soap  or  candle  manufac- 
turers now  render  their  own,  but  there  are  perhaps  many 
places  in  this  country  where  the  rough  fat  could  be  readily 
and  cheaply  purchased,  when  it  would  be  advantageous  for 
them  to  render  it  themselves.  For  those  who  may  have  these 
facilities  it  may  be  necessary  to  give  some  description  of  the 
usual  method  of  rendering  the  fat  used  in  the  arts  of  making 
soap  and  candles. 

The  fresh  fats  are  dried  by  exposing  to  the  air  or  a  warm 
room,  care  being  taken  that  they  do  not  become  offensive; 
when  they  are  reduced  to  small  pieces  by  means  of  a  chop- 
ping board,  Fig.  74,  which  consists  of  a  strong  table  having 
a  long  sharp  knife  B,  under  which  is  placed  a  hard  wood 
board  D,  which  can  be  replaced  when  worn.     For  larger 


464 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


operations  a  power  machine  for  cutting  tallow,  Fig.  75,  is  a 
much  more  expeditious  mode.    In  the  hopper  the  rough  fat 


is  placed,  when  the  knives  upon  the  cylinder  soon  cut  it  into 
small  pieces.  A  still  better  mode  is  to  reduce  it  by  means 
of  a  mill  having  polished  iron  rollers  similar  to  the  mill  used 
for  toilet  soaps,  Fig.  70,  page  435  ;  this  mill  breaks  the  mem- 
branes so  thoroughly  that  the  fats  are  rendered  sooner  and 
better.  The  kettles  for  rendering  in  small  factories  by  an 
open  fire  are  similar  to  Fig.  76.  B  is  the  caldron  ;  0,  steps  to 
facilitate  the  stirring,  filling,  etc. ;  the  caldron  is  egg-shaped, 
heated  only  at  the  base,  and  to  prevent  burning  there  should 
always  be  a  portion  of  melted  fat  in  the  bottom,  for  if  allowed 
to  burn,  the  color  is  so  injured  that  it  cannot  be  bleached. 
When  in  operation  the  fat  requires  almost  constant  stirring^ 
and  the  heat  due  regulation. 

When  the  fat  is  melted  it  is  strained  with  the  sieve  G, 
into  the  pan  E,  in  which  it  is  left  to  cool  and  harden. 
Steam  is  a  great  assistance  in  these  operations,  and  the  fats 


MATERIALS  FOR  CANDLES. 


465 


are  rendered  by  its  aid  in  kettles  or  jacket,  such  as  are  illus- 
trated in  Fig.  18,  page  219. 


Fig.  W. 


In  the  rendering  of  tallows  there  is  much  offensive  gas 
liberated,  which  is  often  a  great  annoyance  to  the  neighbor- 
hood. This  evil  and  the  remedies  are  treated  in  our  section 
on  soap  materials.  For  remedying  this  trouble  in  a  great 
degree,  it  is  customary  to  have  a  hood.  Fig.  77,  placed  over 


Fig.  77. 


the  kettle,  and  which  is  raised  or  lowered  at  pleasure,  and 
conducts  the  disagreeable  vapors  into  the  chimney. 

80 


very  suitable  one,  and  Fig.  79  an  iron  cullendered  box  with 
the  pressed  cake  of  cracklings. 

Fig.  79. 


MATERIALS  FOR  CANDLES. 


467 


A  newer  invention,  of  greater  power,  is  the  elbow  press  of 
Messrs.  Boomer  &  Boscliert  of  Syracuse,  I^.  Y.  (Figs.  80  and 
81).    The  cracklings  are  often  heated  the  second  time,  and 


Fig.  80. 


Fig.  81 


468  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


again  subjected  to  pressure  to  obtain  as  much  tallow  as  is 
possible  by  this  process.  For  rendering  fat  on  a  larger  scale, 
the  steam  digesters  of  Wilson  are  much  used  for  all  descrip- 
tions of  fats.  (See  Fig.  2,  on  page  87.)  By  this  means  there 
is  but  a  small  percentage  of  greaves,  the  fat  being  almost 
entirely  extracted. 

For  a  large  business  we  show  two  other  presses  (Figs.  82 
and  83,  also  by  Boonier  &  Boschert)  very  suitable  for  all  the 
purposes  described  in  this  work  where  a  press  is  used. 


Fig.  82. 


In  Fig.  83  is  seen  the  largest  press,  having  immense  power, 
and  very  useful  for  stearic  acid,  paraffine,  etc.  The  advantage 
of  the  elbow  is  that  the  power  is  graduated,  by  being  tirst 
gentle  and  increasing  as  it  is  straightened. 

For  candles  the  rendered  tallow  is  usually  purified,  to  ac- 
complish which  there  are  various  means,  and  for  the  better 


MATERIALS  FOR  CANDLES. 


469 


in  a  large  vessel  and  permit  it  to  cool  very  slowly,  when  the 
stearin  and  palmitin  will  grain  or  crystallize,  and  collect 
towards  the  edges,  while  the  olein  of  the  non-liquid  part  will 
be  left  free  in  the  centre,  when  it  can  be  ladled  off,  or, 
what  is  still  better,  it  can  be  pressed  out  with  the  presses 


470 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


already  mentioned.  For  this  purpose  the  centrifugal  mill 
has  been  constructed  (Fig.  84).    It  consists  of  a  drum  A  with 

Fig.  84, 


a  circumference  of  gauze  wire  B;  and  has  an  exterior  jacket 
C,  and  the  drum  is  attached  to  a  shaft  D  drawn  by  the  gear- 
ing E.  The  granulated  fat,  tallow  or  lard,  being  placed  in 
the  drum,  it  is  driven  at  great  speed  ;  the  centrifugal  action 
throws  the  granulated  fat  against  the  wire  gauze,  which  re- 
tains the  solid  particles,  while  the  liquid  escapes  through  the 
meshes  into  the  outer  jacket,  and  is  drawn  off  by  the  cock  F. 
This  machine  works  with  great  rapidity  ;  it  is  about  four 
feet  in  diameter,  and  requires  about  one  horse  power  to  drive 
it.  After  the  liquid  part  of  the  tallow  is  extracted,  the  re- 
maining stearin  w^ill  be  whiter  and  harder,  the  olein  having 
the  greatest  amount  of  color. 

Other  processes  for  whitening  tallow,  and  which  harden  it 
at  the  same  time,  are  by  means  of  chemicals.  Watts'  method 
of  bleaching  tallow  is  with  sulphuric  and  nitric  acids,  com- 
bined with  bichromate  of  potash  and  oxalic  acid.  These 
substances  cause  the  liberation  of  oxygen,  which  whitens  the 
fats  very  satisfactorily.  Watson's  process  for  purifying  and 
w^iitening  is  by  means  of  permanganate  of  potash  with  dilute 
sulphuric  acid.  The  permanganate  is  mixed  with  the  melted 
fat,  and  free  steam  blown  through  it,  or  it  is  briskly  stirred, 
when  sufficient  dilute  sulphuric  acid  is  poured  in  and  the 
heat  regulated  not  to  exceed  the  boiling  point  of  water, 


MATERIALS  FOR  CANDLES. 


471 


100°  C.  (212°  F.),  after  which  it  is  allowed  to  rest,  that  the 
melted  tat  may  rise  to  the  top,  and  the  acid  solution  subside 
to  the  bottom.  The  tallow  is  then  placed  in  another  vessel 
and  washed  with  hot  water.  It  is  often  tested  to  ascertain  if 
sufficiently  bleached,  and  if  not,  the  first  process  is  repeated 
to  insure  a  perfect  whiteness. 

There  are  numerous  formulas  for  bleaching  the  fat,  as 
boiling  with  culinary  salt  and  alum  in  a  portion  of  water;  or 
melting  with  about  one  per  cent,  of  acetate  of  lead,  keeping 
it  at  the  melting  point  for  some  15  or  20  hours,  and  turning 
off  the  heat  and  leaving  to  rest  and  harden.  In  the  case  of 
lard  the  pressed  fat  is  melted,  and  one  and  a  half  per  cent,  of 
nitric  acid  is  stirred  with  it  for  some  hours.  This  forms  the 
elaidic  acid — a  beautiful  white  solid  grease,  and  this  was,  we 
believe,  the  first  process  in  use  for  making  candles  from  lard. 

Candles  made  from  these  hardened  and  whitened  fats 
obtain  the  name  of  stearin  candles,  though  the  term  is  now 
generally  applied  to  the  candles  made  of  stearic  acid. 

Stearic  acid,  now  generally  used  for  the  better  class  of 
candles,  is  seldom  perfectly  pure,  nor  is  it  necessary,  except 
to  have  it  as  free  as  possible  from  oleic  acid  and  glycerine,  atid 
to  insure  a  high  melting  point.  To  obtain  it  pure  the  pressed 
tallow  or  stearin  is  saponified  with  potash,  decomposing  the 
soap  with  hydrochloric  acid,  collecting  the  flocculent  stearic 
acid  on  a  filter,  washing  with  cold  alcohol,  and  then  dis- 
solving in  boiling  alcohol.  The  solution  is  then  gradually 
cooled,  when  the  stearic  acid  will  crystallize  in  beautiful 
nacreous  leaflets.  It  is  tasteless  and  odorless,  dry  to  the 
touch,  and  can  be  powdered;  its  melting  point  is  about  70^  C. 
(158°  F.),  and  it  has  a  slight  acid  reaction  with  blue  litmus 
paper. 

Stearic  acid  for  candles  is  prepared  in  many  ways,  some  of 
which  have  been  abandoned  in  practice  as  too  laborious  or 
expensive.  The  whole  object  of  these  processes  is  to  dis- 
associate the  fats  from  their  glycerine  and  the  greater  portion 
of  their  oleic  acid. 

The  processes  still  in  use^  each  having  its  advocates,  may 
be  classed  under  the  following  heads: — 


472  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


1.  Saponification  by  lime. 

2.  Saponification  with  a  little  lime  assisted  with  water  and 
pressure. 

3.  Saponification  by  sulphuric  acid  and  subsequent  distil- 
lation. 

4.  Saponification  by  sulphuric  acid. 

5.  Saponification  by  water  combined  with  distillation. 

6.  Saponification  by  water  under  high  pressure. 

The  Saponification  by  Lime. — The  decomposition  of  the 
neutral  fats  by  means  of  lime  and  the  separation  of  the  gly- 
cerine is  conducted  on  a  larger  scale  in  a  tun  provided  for 
the  purpose  having  a  stirring  apparatus  consisting  of  a  cen- 
tral shaft  with  four  brass  arms  studded  with  large  teeth  as 
shown  in  Fig.  85.   Heat  is  communicated  by  the  convoluted 

Fiff.  85. 


steam  pipe  placed  in  the  bottom  having  perforations  for  the 
escape  of  the  steam,  which  is  regulated  by  an  outside  valve. 
In  this  tun  hydrate  of  lime  in  the  form  of  milk  of  lime  is 
mixed  with  the  fat  in  the  proportion  of  15  per  cent.;  the 
lime  should  be  as  pure  as  possible  and  caustic,  or  a  larger 
amount  of  acid  will  be  needed  to  neutralize  it,  and  the  im- 


MATERIALS  FOR  CANDLES. 


473 


Jwrities  are  difficult  of  removal  from  the  fatty  acid.  The 
milk  of  lime  having  been  thoroughly  combined  with  the 
tallow,  the  cover  is  fastened  down  and  the  steam  turned  on 
whWe  the  stirrer  revolves;  after  six  hours,  when  the  combi- 
nation should  be  complete,  the  heat  is  turned  off,  and  it  is 
left  to  cool. 

To  test  if  the  saponification  is  perfect,  take  out  a  small 
portion  of  the  thick  mass  and  allow  it  to  deposit  the  lime 
soap ;  \he  supernatant  water  is  poured  off  and  the  soap  cooled. 
If  it  is  smooth,  homogeneous,  and  semi-transparent,  it  makes 
a  sharp  ring  when  broken,  and  can  be  powdered  in  a  mortar, 
there  ia  no  decomposed  fat.  The  steaming  should  be  con- 
tinued until  the  reactions  are  complete;  the  steam  is.  then 
shut  off  and  a  quantity  of  cold  water  added,  keeping  up  the 
agitation.  This  washing  with  cold  water  causes  the  insolu- 
ble lime  soap  to  assume  a  granular  appearance,  and  as  soon 
as  this  is  effected  the  agitation  is  discontinued. 

When  after  a  short  time  the  whole  has  settled,  the  water 
with  the  glycerine  in  solution  is  drawn  off  by  means  of  a 
cock  in  the  bottom  whose  mouth  is  protected  with  a  wire 
gauze  so  that  no  soap  can  pass  through.  When  all  the  water 
is  withdrawn,  the  outlet  is  stopped  off,  and  more  cold  water 
poured  in  and  again  agitated ;  this  is  drawn  off  as  before.  By 
these  repeated  washings  all  the  glycerine  is  removed,  and 
nothing  remains  but  the  lime  soap  of  stearic,  palmitic,  and 
oleic  acids,  and  perhaps  a  little  excess  of  lime. 

The  next  step  of  the  process  is  the  decomposition  of  the 
soap  and  the  removal  of  the  lime.  This  is  done  with  sul- 
phuric acid  in  the  proportion  of  25  per  cent,  diluted  with 
eight  times  its  weight  of  water.  The  diluted  acid  is  gradu- 
ally added,  the  mixture  heated  to  about  93°  C  (199.4°  F  ), 
and  no  higher;  it  is  gently  agitated  till  the  decomposition  is 
complete,  which  is  determined  by  the  disappearance  of  the 
granular  structure  and  the  rising  of  the  fatty  bodies  to  the 
surface.  Much  care  is  necessary  at  this  period  in  regulating 
the  entrance  of  steam  and  the  temperature,  for  if  the  heat  is 
too  great  the  color  may  be  injured.  The  tun  may  be  left 
uncovered  during  this  decomposition  without  any  disadvan- 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


tage.  When  the  separation  of  the  lime  is  complete  the  con- 
tents of  the  tun  are  left  to  rest  for  some  time,  in  order  tlat 
the  sulphate  of  lime  may  be  entirely  taken  up  by  the  W2ter 
and  removed  from  the  fats  that  occupy  the  upper  stratum. 
The  cock  at  the  bottom  is  then  opened  and  all  the  liquid 
with  the  salts  drawn  off.  Hot  water  is  now  let  in  and  the 
agitator  set  in  motion  to  wash  out  any  lime  or  salts,  and 
after  a  time  the  liquid  is  again  left  to  rest  as  before  till  the 
water  and  impurities  have  settled  to  the  bottom,  when  they 
are  drawn  off  through  the  outlet.  This  washing  is  repeated 
till  all  traces  of  the  mineral  contents  are  separated,  when  the 
fatty  acids  are  brought  to  the  melting  point  and  drawn  off 
into  trays  to  crystallize. 

The  trays,  made  of  heavy  tin  plate,  are  about  18  inches 
long,  12  broad,  and  'd  deep.    Figs.  86  and  87  represent  a 

Fig.  86.  Fig.  87. 


wooden  framework  A,  bound  by  transverse  bars  of  iron  B, 
which  support  the  trays  C  C  at  the  same  time.  F  F  are 
leaden  funnels  for  running  the  fatty  acids,  G  a  wooden  plug 
for  stopping  them.   The  trays  are  kept  in  a  convenient  room 


MATERIALS  FOR  CANDLES 


475 


where  the  temperature  stands  at  about  22°  to  82°  C.  (71.6'" 
to  89.6°  F.),  that  they  may  cool  slowly  for  several  days — till 
the  fatty  acids  assume  a  crystalline  form,  or  granulate.  At 
this  temperature  oleic  acid  does  not  solidify,  and  may  be  ob- 
served in  drops  exuding  from  the  solid  fats  in  the  trays. 

AVhen  the  mass  in  the  trays  has  granulated  as  far  as  pos- 
sible, it  is  removed  to  a  machine  and  cut  in  thin  shreds 
with  knives  attached  to  a  revolving  wheel  (similar  to  the 
soap  stripper  or  the  rasping  machine  for  spermaceti,  Fig.  94, 
page  484),  the  divided  fat  is  then  placed  in  canvas  bags 
and  pressed  either  in  a  hydraulic  press  or  the  elbow  presses 
of  Messrs.  Boomer  and  Boschert,  Syracuse,  I^".  Y.  (see  Figs. 
80,  81,  82,  and  83  j,  and  the  chief  part  of  the  oleic  acid  pressed 
out.    In  placing  in  the  press  every  two  bags  are  separated 

Fi.nr.  88. 


c 

} 

u 

1 


by  a  plate  of  sheet  iron  with  turned-up  rim;  this  prevents 
the  mass  from  sticking  together  by  the  great  pressure,  and 
the  canals  of  the  plate  collect  the  oleic  acid.    Fig.  88  is  the 
usual  form  of  hydraulic  press. 
When  no  more  oil  exudes,  the  press  is  loosened  and  the 


476 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


layers  removed  :  by  this  pressure  the  fat  cakes  become  so 
hard  that  the  linger-nail  can  scarcely  make  any  impression, 
but  they  still  retain  oleic  and  palmitic  acid,  to  remove  which 
it  is  necessary  to  submit  them  to  a  second  pressure  aided  by 


Fig.  89. 


heat,  particularly  if  the  fat  is  required  for  the  best  stearic 
acid  candles.    Fig.  89  is  a  drawing  of  the  hydraulic  press 


Fig.  90. 


for  hot  pressing,  and  Figs.  90,  91,  and  -92  explain  the  work- 
ing parts.    Steam  is  conveyed  by  means  of  the  movable 


MATERIALS  FOR  CANDLES. 


477 


telescoping  tubes  into  the  press  plates  which  are  of  iron  hav- 
ing: a  vvindins:  channel  for  the  entrance  of  the  steam  which 
furnishes  the  heat.  The  fat  cakes  are  asjain  reduced  to  shreds 


Fig.  91. 


Fisr.  92. 


and  placed  in  bags,  and  these  enveloped  in  stronger  ones  of 
coarse  jute-fibre  or  horsehair,  and  placed  in  the  same  man- 
ner in  the  horizontal  press  between  the  heated  plates,  and 
when  sufficiently  pressed  taken  out ;  when  it  can  at  once  be 
used  for  moulding  adamantine  or  stearic  acid  candles.  If, 
however,  a  purer  article  is  needed  for  the  best  stearic  acid 
candles,  a  further  saponification  is  necessary.  The  fatty  acid 
is  again  melted  and  submitted  to  free  steam  for  5  to  8  hours, 
or  until  it  is  perfectly  bleached. 

De  Milly's  Process. — De  Milly  has  simplified  this  lime  pro- 
cess by  using  only  2  to  4  per  cent,  of  lime  aided  by  a  high 


478 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


steam  pressure  of  150  pounds  at  a  temperature  of  182°  C, 
(359.6°  F.). 

Tallow  treated  in  this  way  is  saponified  in  about  6  hours. 
The  style  of  boiler  employed  by  him  was  a  large  upright 
cylinder  of  copper,  provided  with  safety  valve  and  gauge 
with  pipes  for  the  entrance  of  surcharged  steam,  and  for 
filling  and  drawing  off  the  contents;  the  ends  both  top  and 
bottom  were  rounded,  and  the  whole  set  in  heavy  masonry. 
In  using  this  boiler  the  tallow  is  put  in  with  an  equal  weight 
of  water,  less  the  quantity  used  in  making  the  milk  of  lime, 
which  is  added  by  degrees  so  as  not  to  arrest  the  ebullition, 
and  continued  until  a  complete  emulsion  is  formed  ;  when 
this  occurs,  the  safety-valve  is  closed,  allowing  on]y  a  small 
escape  of  steam,  causing  a  continued  movement  of  the  con- 
tents. The  tem[)erature  is  gradually  elevated  to  a  pressure 
of  8  atmospheres,  about  175°  C.  (847°  F.),  when  the  flow  of 
steam  is  arrested  so  as  to  maintain  tiie  temperature  at  this 
point  for  at  least  four  hours.  The  saponification  may  then 
be  considered  finished,  and  the  contents  can  be  removed  by 
the  proper  valves.  The  subsequent  decomposing,  washing, 
and  pressing  is  similar  to  that  already  described.  This  pro- 
cess has  many  points  of  advantage  and  economy,  saving  lime, 
acid,  and  waste  of  fatty  material. 

The  sapomjicaiion  by  sulphuric  acid  has  long  been  known, 
but  has  not  until  lately  found  a  practical  application.  The 
process  as  now  conducted  may  be  described  as  follows: — 

The  fats  are  placed  in  large  lead-lined  vessels,  with  six 
to  fifteen  per  cent,  of  concentrated  sulphuric  acid  ;  the  mix- 
ture is  heated  by  a  steam  coil  to  nearly  the  temperature 
of  boiling  water  for  eighteen  or  twenty'  hours  ;  some  operate 
at  a  higher  temperature  and  save  time  in  the  reaction,  and 
also  use  a  larger  amount  of  acid.  The  fat  is  decomposed 
with  an  alteration  of  part  of  the  glycerine,  and  part  of  the 
fat,  sulphidic  and  carbonic  acids  being  evolved.  The  black 
mass  resulting  from  the  action  is  now  thoroughly  washed 
with  boiling  water  until  all  the  fatty  acids  are  freed  from 
the  sulphuric  acid.  The  fatty  acids  are  now  put  into  a  large 
still  and  heated  from  below  to  a  temperature  of  260°  C. 


MATERIALS  FOR  CANDLES. 


479 


(500°  F.),  when  a  jet  of  superheated  steam  of  350°  to  380° 
C.  (662°  to  716°  F.),  is  run  through  the  charge ;  in  about  12 
hours  the  matter  is  distilled  over,  leaving  behind  a  pitchy 
substance  which  can  be  used  for  many  useful  purposes  in 
the  arts.  The  fatty  acids  are  cooled  in  the  trays,  and  can 
be  submitted  to  cold  and  hot  presses  as  before  described. 
When  palm  oil  has  been  used,  it  is  often  made  into  candles 
without  further  manipulation.  This  process  we  think  has 
no  advantage  over  the  lime  process  described,  unless  refuse 
or  common  fats  are  used. 

Saponification  by  sulphuric  acid  without  distillation  may  be 
described  as  conducted  by  De  Milly.  The  fat  is  heated  to 
120^  C.  (248°  F.),  it  is  then  caused  to  flow  in  a  small  stream 
and  mix  with  a  stream  of  strong  sulphuric  acid  in  the  pro- 
portion of  six  per  cent,  of  the  latter;  the  mixture  being 
briskly  stirred,  the  action  takes  place  at  once  and  is  arrested 
in  two  or  three  minutes  by  allowing  the  mixture  to  flow 
into  boiling  water,  when  the  sulphuric  acid  and  unaltered 
glycerine  unite  with  the  water,  and  the  fatty  acids  float  upon 
the  surface  and  are  of  a  dark  color.  But  these  acids  are  quite 
different  from  those  in  the  method  before  described;  here  the 
coloring  matter  is  soluble  in  the  liquid  fatty  acid,  so  that  by 
pressing  both  cold  and  hot  the  solid  acids  are  obtained  almost 
or  quite  white,  ready  to  be  moulded  into  candles.  The  entire 
operation  can  be  conducted  in  about  an  hour's  time;  yet, 
if  the  cold  pressure  has  not  furnished  the  solid  acid  free 
from  color,  it  is  advisable  to  melt  it  again  and  granulate  it 
in  the  trays  and  again  press  it;  when  a  fatty  acid  fusible 
at  about  56°  0.(132  8^  F.)  is  obtained  admirably  adapted 
for  the  best  stearic  acid  candles. 

Saponification  of  fats  by  water  combined  with  distillation. — 
This  process,  though  hinted  at  by  Chevreul  and  Gay  Lussac 
and  practised  by  Dubrunfault,  was  not  a  complete  success. 
But  Mr.  George  Wilson,  of  the  Price  Candle-works  near 
London,  carried  it  to  a  practical  success,  at  least  when  palm 
oil  was  the  fat  employed.  In  accomplishing  this  result, 
he  heated  the  fat  to  a  temperature  of  290°  to  315°  C.  (554° 
to  599°  F.),  and  passed  through  the  fat  a  current  of  sur- 


480  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


charged  steam  of  the  same  temperature.  This  great  heat 
was  necessary,  otherwise  the  distillation  was  very  slow,  and 
acrolein  was  formed.  The  glycerine  obtained  by  this  pro- 
cess is  of  good  quality,  and  when  purified  is  the  well-known 
Price's  glycerine.  It  may  be  well  to  remark  that  this  pro- 
cess, when  other  fats  than  palm  oil  were  employed,  did  not 
give  so  satisfactory  a  result,  so  that  it  has  but  a  limited 
application. 

Saponijication  by  water  under  high  pressure. — When  the  true 
nature  of  the  fats  was  discovered,  it  gave  rise  to  many  theo- 
ries that  eventually  became  of  practical  utility.  Faraday 
pointed  out  this  process  as  long  ago  as  1825,  and  Tilghman 
took  out  a  patent  in  1854,  but  has  not  yet  we  believe  put  it 
into  practice.  M.  Melsens,  of  Belgium,  has,  however,  suc- 
ceeded, and  works  have  been  put  up  at  Antwerp,  where  vessels 
holding  a  ton  of  tallow  are  used ;  fifty  per  cent,  of  water  is 
added  and  heated  to  a  temperature  of  180°  C.  (356^  F.)— ten 
or  more  atmospheres.  In  six  hours  the  decomposition  is 
complete,  and  the  fatty  acids  produced  are  of  a  satisfactory 
quality,  indeed,  as  good  as  result  from  more  complicated 
processes.  This  process  we  think  deserves  much  considera- 
tion from  its  simplicity  and  economy  of  time,  and  moreover, 
from  the  purity  of  the  glycerine  so  obtained,  this  article 
having  great  commercial  value. 

The  oleic  acid  recovered  from  various  processes  finds  a 
ready  application  in  the  manufacture  of  soaps,  some  of  the 
best  domestic  soaps  being  made  of  it,  used  alone  or  in  com- 
bination with  other  fats  or  rosin.  That  furnished  by  the 
lime  process  claims  a  preference  to  that  from  the  acid,  the 
latter  requiring  more  alkali  and  more  time  to  make  it  into 
soap.  The  methods  of  its  saponification  have  received  full 
attention  in  another  part  of  this  work.  Olein  when  purified 
is  also  used  in  fulling  wool  and  dressing  leather.^ 

'  Some  of  the  latest  information  regarding  the  sebacic  or  fatty  acids  is 
given  by  Prof.  T.  Kraft,  in  his  Reports  to  the  German  Chemical  Society  of 
October,  1879,  as  follows : — 

"Palmitic  acid  obtained  from  palm  oil  melts  at  620  C.  (143.60  P.),  and 
boils  under  a  pressure  of  100  millimetres  at  268. 5^  C.  (515.4°  F.).  Keton, 


MATERIALS  FOR  CANDLES. 


481 


A  distilling  apparatus  in  which  the  surcharged  steam  is 
brought  to  aid  the  processes  here  described,  is  here  repre- 
sented in  Fig.  93.    Tbe  flat  metal  boiler  D  with  dome-shaped 

Fig.  93. 


cover  is  heated  by  the  waste  heat  of  the  super-heater,  the 
fluid  fat  is  let  into  the  copper  boiler  A,  the  cock  d  serves  to 
regulate  the  flow.  The  dome  cover  B  o'i  the  boiler  has  a 
cap  of  iron  B  B,  which  is  heated  with  coals  to  prevent  loss  of 
heat  by  radiation.  The  steam,  being  heated  from  248.8°  to 
304.4°  C.  (480°  to  580°  F.)  and  let  into  the  boiler  A,  changes 
the  fats  into  fatty  acids  and  glycerine,  and  the  vapors  rising 
with  the  steam  are  carried  into  the  pipes  L  and  X  and  to 
the  condenser  0  0.  The  steam  excludes  the  air  from  the 
interior  of  the  boiler,  and  thus  promotes  the  saponification, 

C1.H34O,  being  obtained  of  equal  weight  parts  of  acetate  of  barium  and 
palmitic  acid  barium,  melts  at  48°  C.  (118. 4°  F.),  and  boils  under  a  pressure 
of  100  millimetres  at  246°  C.  (474. 8°  F.),and  under  normal  pressure  at  31 90  C. 
(606.20  F.).  By  oxidation  with  bichromate  of  potassium  and  sulphuric  acid, 
pentadecyl-acid  is  obtained  =  C15H38O2,  which  melts  at  55°  C.  (1310F.), 
and  boils  under  100  millimetres  pressure  at  266. 5°  C.  (511. 80  F. ).  By  oxi- 
dation with  bichromate  of  potassium  and  diluted  sulphuric  acid,  we  obtain 
the  margarinic  acid  C17H34O2,  which  Heintz  had  already  prepared  in  a  far 
more  intricate  way.  The  oxide  of  silver  of  this  acid  corresponds  to  the 
formula  AgCnHagO,.  It  melts  at  59.80  C.  (139.60  F.),  'and  boils  under 
100  millimetres  pressure  at  277°  C.  (530.6°  F.)." 
31 


482 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES, 


SECTIOIT  III. 

MATERIALS  FOR  CANDLES  (Continued). 

Paraffine. — Perhaps  the  material  next  in  importance  to 
stearic  acid  for  making  candles  is  -paraffine^  called  paraffine 
wax — a  valuable  hydrocarbon  extracted  from  bituminous 
coal,  shales,  peat,  lignite,  petroleum,  etc.  The  process  for  ob- 
taining paraffine  from  all  these  different  substances  is  gene- 
rally the  same.  The  materials  are  placed  in  retorts  of  a  certain 
construction,  and  heated  to  a  low  red  heat.  The  outlet  of  the 
retort  communicates  with  a  simple  condenser  cooled  with 
water  or  a  large  surface  of  air.  A  current  of  steam  passing 
through  the  retort  greatly  assists  the  distillation.  Ammoni- 
acal  vapors  first  pass  over,  then  brown  vapors  of  the  more 
volatile  hydrocarbons,  which  continues  with  increased  density 
until  the  materials  are  reduced  to  coke.  The  crude  oil  thus  ob- 
tained is  a  kind  of  brown  tar  floating  in  a  quantity  of  water 
which  has  absorbed  the  ammoniacal  fumes.  The  crude  oil  is 
again  distilled,  and  then  agitated  with  strong  sulphuric  acid, 
and  left  to  rest  for  a  while,  that  the  carbonaceous  impurities 
may  be  taken  up  by  the  acid  and  subside  and  be  removed. 
Any  acid  that  may  remain  in  the  oil  is  neutralized  with  soda, 
and  the  oil  is  now  distilled  fractionally.  The  first  and  more 
volatile  naphtha,  termed  "  spirit,"  is  run  into  one  tank  ;  next 
a  heavier  oil,  called paraffine  oil,"  for  burning  ;  and  thirdly, 
a  heavy  oil  for  lubricating,  etc.  This  last  running  contains 
the  paraffine  or  wax.  To  separate  this  wax  the  oil  con- 
taining the  crystalline  scales  is  reduced  to  the  freezing  point, 
then  bagged  and  pressed  in  presses  such  as  w^e  have  before 
illustrated.  The  "  paraffine  scale"  thus  separated  is  of  a 
brown  or  yellowish  tinge,  and  requires  further  purification  ; 
this  is  efiected  by  putting  it  into  the  trays,  and  cooling 


MATERIALS  FOR  CANDLES. 


483 


very  slowly  that  it  may  crystallize.  The  cakes  are  then 
placed  upon  some  porous  substance,  and  exposed  to  a  tem- 
perature just  sufficient  to  melt  the  more  fluid  parts,  which 
flow  out  from  between  the  crystals;  this  is  continued  until 
the  solid  and  liquid  parts  are  separated  as  much  as  possible. 
The  solid  parts  are  again  melted  together,  and  again  puri- 
fied by  melting  by  steam  and  adding  5  to  10  per  cent,  of 
strong  sulphuric  acid  and  agitating  some  hours.  After 
allowing  the  whole  to  rest  for  some  time  to  permit  the  mass 
to  separate,  the  paraffine  is  drawn  oflT  and  digested  with 
animal  charcoal,  which  is  allowed  to  subside,  and  the  liquid, 
if  not  yet  clear,  is  filtered  in  a  double  filter  kept  warm  by 
steam. 

Later  processes  for  bleaching  paraffine  are  in  vogue,  using 
fuller's  earth,  silicate  of  magnesia,  or  lime,  with  marked 
success  ;  in  fact  there  are  very  many  new  processes  for  this 
manufacture,  but  we  think  we  have  given  the  simplest. 

The  value  of  paraffine  for  candles  depends  upon  its  melt- 
ing point,  which  varies  very  much,  depending  upon  the  source 
of  manufacture,  and  is  from  35°  to  65°  0.  (95°  to  149°  F.), 
and  much  care  should  be  exercised  in  having  that  of  the 
highest  before  making  into  candles.  Paraffine  from  lignite 
or  petroleum  has  a  low  melting  point,  that  from  ozokerite 
(a  peculiar  wax-like  mineral)  has  a  very  high  one,  65.5°  C. 
(150°  F.),  and  paraffine  is  of  all  the  intermediate  grades. 
Stearic  acid  and  some  of  the  vegetable  waxes  are  added  to 
paraffine  to  obviate  its  tendency  to  soften,  which  it  often 
does,  below  its  melting  point,  which  causes  the  candles  to 
bend  and  become  misshapen. 

From  numerous  sources  are  made  similar  substances  to 
paraffine,  and  called  by  as  many  names,  but  they  are  analo- 
gous substances  from  a  mineral  source  having  nearly  the 
same  constituents  and  specific  gravit}^,  and  there  are  many 
patented  candles  which  have  these  matters  for  the  base  com- 
bined with  wax,  spermaceti,  stearic  acid,  etc.  Black  paraf- 
fine candles  are  seen  that  are  colored  with  anacardian  shells. 

Spermaceti  must  next  claim  our  notice,  for  this  substance 
is  perhaps  one  of  the  best  for  the  purpose  of  making  a 


484  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


beautiful,  transparent,  pearl-like  candle,  giving  a  white  light 
of  high  illuminating  power,  burning  with  great  regularity, 
yet,  owing  to  the  cheapness  of  other  materials  for  this  pur- 
pose, these  candles  are  too  expensive  for  ordinary  use,  particu- 
larly as  the  material  seems  to  become  scarcer  year  by  year. 
Spermaceti  is  the  solid  portions  of  the  crude  spermaceti,  or 
"  head  matter"  of  the  sperm  whale,  Physter  macrocephalus, 
and  some  other  of  the  cetacea ;  it  is  obtained  by  filtration 
from  the  oil,  purified  with  steam  and  weak  alkali,  and 
hardened  by  pressure  in  the  same  manner  as  that  given  for 
stearic  acid.  The  crystallized  cakes  are  reduced  to  shreds  by 
a  machine  represented  by  Fig.  94,  the  cakes  being  placed  on 


Fig.  94. 


D  and  cut  by  the  knife  C,  the  grains  falling  into  the  chest 
A,  from  which  they  are  transferred  to  the  bags  and  pressed 
in  the  press  illustrated  elsewhere,  and  purified  as  mentioned. 

According  to  Heintz,  spermaceti  is  a  combination  of  cetyl 
with  stearic,  palmitic,  myristic,  cocinic,  and  cetinic  acids. 
Owing  to  the  tendency  of  spermaceti  to  crystallize  in  mould- 
ing, it  is  common  to  add  a  little  white  wax  or  some  paraflSne, 
which  with  proper  manipulation  gives  the  desired  structure 
to  the  candles. 

Wax  of  various  origin,  animal  and  vegetable,  is  used  for 
making  candles,  the  most  useful  being  beeswax,  which  is 


MATERIALS  FOR  CANDLES. 


485 


now  decided  to  be  a  secretion  of  the  bee,  and  not  from  the 
plants  they  feed  upon,  as  was  at  first  supposed.  Beeswax 
is  obtained  in  commerce,  of  a  more  or  less  dirty  color  and 
very  impure,  and  has  to  be  bleached  to  render  it  fit  for  can- 
dles, tbe  best  process  for  this  purpose  being  exposure  to  sun 
and  air. 

The  first  step  in  tbese  operations  is  to  boil  the  wax  with 
water,  with  a  small  portion  of  alum  and  dilute  sulphuric 
acid  ;  boiling  and  stirring  for  some  time,  the  impurities  are 
allowed  to  subside,  it  is  then  dipped  into  a  cullender  attached 
to  a  machine  where  it  falls  upon  a  cylinder  of  polished  hard- 
wood kept  wet  by  revolving  in  the  ^vater  beneath,  and  is  thus 
reduced  to  ribbons.  It  is  then  carried  to  a  framework  upon 
which  is  stretched  a  cotton  cloth,  and  being  placed  on  this 
cloth  it  is  frequently  stirred  and  sprinkled  with  water  that 
the  sun  and  air  may  act  on  all  the  surfaces.  If  the  wax 
upon  being  remelted  has  not  acquired  suflicient  whiteness, 
these  operations  will  have  to  be  repeated.  Beeswax  is  often 
bleached  with  chemicals ;  the  most  efiicient  being  bichro- 
mate of  potash  with  a  little  sulphuric  acid  ;  the  process 
seems,  however,  to  alter  the  better  properties  of  the  wax, 
making  it  hard  and  brittle. 

Other  waxes. — Many  other  waxes  are  known  in  commerce  : 
Chinese  wax,  from  a  kind  of  coccus  insect.  Coccus  cerifera^ 
feeding  on  the  Rhus  succedanea  ;  Japan  wax,  though  not  a  wax 
proper,  containing  palmitin  and  glycerine,  is  of  a  good  white 
color,  though  apt  to  change  on  exposure ;  Pela  wax,  obtained 
from  a  species  of  palm  called  vegetable  spermaceti,  has  a 
high  fusion  point,  being  82°  C.  (179.6°  F.) ;  Myrtle  wax,  from 
the  Myrica  cerifera^  found  in  our  Southern  States.  Carnauba 
wax,  received  from  South  America,  is  a  very  hard  and  valu- 
able wax,  having  a  melting  point  as  high  as  84°  C.  (183.2° 
F.).  Ocuba  wax,  also  received  from  the  Brazils,  has  rather  a 
low  fusion  point,  being  40°  C.  (104°  F.).  Many  of  these 
vegetable  waxes  and  tallows  could  be  used  for  candles  if 
procured  at  low  prices,  as  they  might  by  their  properties 
correct  some  of  the  objectionable  ones  of  tallow,  stearin, 
paraffine,  etc. 


486  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Sebacylic  acid  should  receive  some  notice,  as  it  migiit  per- 
haps serve  to  impart  to  [raratiine  and  other  kinds  of  candles 
a  higher  melting  point.  This  acid  is  obtained  by  the  dry 
distillation  of  oleic  acid,  or  better,  b}^  treating  castor  oil 
with  highly  concentrated  caustic  soda  solution ;  its  high  fusion 
point,  127°  C.  (260.6°  F.),  and  its  ready  combustibility  ren- 
der it  a  fit  material  for  melting  with  softer  candle  materials. 

Elaidic  acid,  made  by  the  action  of  nitric  acid  upon  oleic 
acid,  lard  oil,  and  other  oils,  is  also  a  material  that  might 
be  advantageously  used  for  candles.  It  can  be  made  into  a 
beautiful  white  solid.  Its  melting  point,  depending  some- 
what upon  the  source  of  its  manufacture,  ranges  from  38°  to 
43°  C.  (100.4°  to  109.4°  F.),  and,  being  an  article  that  can  be 
made  at  a  small  cost,  it  might  be  mixed  with  other  substances 
for  this  purpose. 

Glycerine,  so  often  alluded  to  in  our  work,  must  not  be 
passed  without  some  notice,  it  being  a  by-product  in  many 
of  the  processes  described  for  the  saponification  and  pre- 
paration of  the  fatty  acids  for  obtaining  the  solid  sebacic 
acids  for  the  manufacture  of  candles.  This  valuable  sub- 
stance is  present  in  all  the  neutral  fats  to  the  amount  of  8  to 
9  per  cent.,  and  may  be  separated  by  treatment  with  the  bases, 
with  acids,  steam,  etc.,  so  often  described  by  us.  It  was  first 
discovered  by  Scheele  in  preparing  lead  plaster.  Glycerine 
is  also  formed  by  the  alcoholic  fermentation  of  glucose, 
etc. ;  the  molasses  from  beet-root  sugar  and  the  residuum  from 
the  distillation  of  wine  also  furnish  glycerine.  In  regard 
to  the  preparation  and  purification  of  glycerine,  when  its 
source  is  from  the  water  after  the  separation  of  the  lime 
soap  in  making  stearic  acid.  The  lime  in  the  w^ater  is 
eliminated  by  sulphuric,  or  preferable,  with  oxalic  acid, 
and  the  liquid  evaporated  to  the  consistency  of  a  syrup, 
forming  a  glycerine  pure  enough  for  many  technical  pur- 
poses. When  the  decomposition  of  the  neutral  fat  isefifected 
with  super-heated  steam,  the  glycerine  and  fatty  acids  are 
both  obtained  comparatively  pure,  provided  the  heat  has  not 
been  too  great.   The  solution  of  glycerine  and  sulphuric  acid 


MATERIALS  FOR  CANDLES. 


487 


in  the  process  by  that  acid  will  yield  the  glycerine  by  evapo- 
ration, and  the  sub-lye  from  the  soap  boilers  is  a  large  source 
of  crude  glycerine.  Glycerine  is  now  largely  employed  in 
many  industries,  such  as  for  keeping  clay  moist  for  modelling, 
preventing  mustard  from  drying  up,  keeping  snuff  damp, 
preserving  fruit,  sweetening  beer  and  liquors,  also  for  lubri- 
cating fine  machinery  ;  in  fact  it  would  take  a  large  space 
to  enumerate  its  many  uses. 


488  TECHNICAL  ;rREATISE  ON  SOAP  AND  CANDLES. 


SECTION  lY. 

THE  MANUFACTURE  OF  CANDLES. 

Wicks  and  their  Preparation. 

To  form  a  correct  estimate  of  the  quality  of  candles  various 
points  have  to  he  studied  ;  we  give  the  following: — 

1st.  The  nature  of  the  fatty  matter  used  in  their  manu- 
facture; 2d.  Their  whiteness;  3d.  Their  transparency; 
4th.  Their  hardness ;  5th.  Their  dryness  to  the  touch;  6th. 
Their  point  of  fusion  ;  7th.  Their  form  and  their  moulding; 
8th.  The  nature  and  kind  of  wick;  9th.  The  nature  of  the 
flame,  if  it  be  uniform,  long  or  short,  well  supplied,  illumi- 
nating, brilliant  looking,  with  or  without  smoke  ;  10th. 
Does  the  capping  at  the  top  of  the  candle  burn  dry,  or  is  it 
more  or  less  filled  with  the  melted  fat?  11th.  Is  the  fatty 
matter  free  from  mineral  substances  ? 

This  list  we  believe  gives  all  the  points  worth  noticing  to 
furnish  a  correct  idea  of  the  quality  of  the  candles  of  com- 
merce. The  point  of  fusion  of  the  best  quality  of  candles 
should  not  fall  below  56°  C.  (132.8°  F.).  Candles  made 
from  the  palm-oil  acids,  though  giving  a  pure  white  light, 
seldom  exceed  51°  C.  (128.8°  F.).  To  obviate  this,  some 
manufacturers  envelop  them  in  a  harder  fat  in  the  moulding; 
this  is  troublesome,  and  consumes  much  time.  Candles  made 
from  the  distilled  acid  give  a  good  light,  but  generally  dis- 
color when  exposed  to  the  air;  for  this  reason  the  stearic  acid 
candles  made  by  the  lime  saponification  usually  rank  the 
highest  in  commerce.  There  are  many  other  kinds  of  can- 
dles known  by  names  peculiar  to  the  manufacturers,  as  star, 
adamantine,  palmitine,  margarine,  composition,  etc.,  but 
they  are  all  made  from  the  materials  already  described,  and 
may  be  a  compound  of  the  different  ingredients  which  by 


MANUFACTURE  OF  CANDLES. 


489 


mixing  may  be  supposed  to  improve  them  or  be  combined 
for  the  sake  of  economy. 

The  wicks  for  candles  require  close  attention,  for  much 
depends  upon  them,  whether  of  the  right  size,  of  uniform 
thickness,  free  from  loose  threads,  knots,  etc.  Cotton  is  now 
the  material  generally  used  for  wicks  for  tallow  candles ;  it  is 
simply  twisted  ;  for  stearin,  paraffine,  and  sperm  candles  the 
wicks  are  plaited,  so  that  when  burning  the  threads  twist 
out  of  the  flame  and  are  consumed,  so  that  snuffing  is  not 
needed. 

For  tallow  candles  the  following  proportions  are  generally 
followed.    "  English  style." 

For  an  8  candle  to  the  pound  38  to  42  threads  of  No.  16. 
"      7  "       "         42  to  45       "        "  16. 

"      6  "       "         49  to  52       "        "  16. 

"      5  "       "         52  to  55       "        "  16. 

"      4  "       "         56  to  62       "  16. 

The  wicks  for  the  stearic  acid,  paraffine,  spermaceti,  and 
many  composite  candles  are  of  a  much  finer  grade,  and  known 
as  number  40  ;  the  following  is  usual: — 

For  an  8  candle  to  the  pound  60  to  64  threads  of  No.  40 
"    6  "        "  85  to  88       "        "  40 

*'    5  *'        "  90  to  100       "        "  40 

"    4  "        "         104  to  108       "        "  40 

The  wicks  before  using  undergo  certain  preparations  by 
steeping  them  in  a  solution  of  either  boracic  acid,  nitrate  of 
soda  or  potash,  chloride  of  ammonia,  etc.,  each  having  its 
advocates,  but  a  solution  of  boracic  acid  with  a  few  drops  of 
sulphuric  acid  is  now  conceded  to  be  the  most  effective. 
They  are  dried  and  soaked  in  the  solution  for  8  or  4  hours, 
when  they  are  taken  out  and  pressed  and  dried  in  a  suitable 
oven.  The  purpose  of  this  preparation  is  to  cause  the  con- 
sumption of  the  ash  of  the  cotton,  and  to  retard  their  com- 
bustion.^ 

'  In  Germany,  Belgium,  Switzerland,  America,  as  in  most  other  countries, 
the  English  style  of  designating  the  degree  of  fineness  of  yarns  is  custom- 
ary. In  order  to  understand  this,  the  following  will  be  sutRcient.  Yarn, 
as  is  well  known,  comes  into  the  market  in  hanks  or  skeins.    The  reel 


490 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


For  the  cutting  of  the  wicks  there  are  many  kinds  of 
machines  more  or  less  convenient.  The  simplest  form  of 
wick  cutter  is  here  shown,  Fig.  95,  C  G  being  the  top,  cl  a 
sliding  top  for  graduating  the  length  of  the  wick,  B  the 
stand  for  the  balls  of  the  wick  A  ;   the  wick  being  cut  of 

the  proper  length  by  the  knife 
Fig.  95.  gr.    For  a  larg-e  business  here 


is  shown  a  very  handy  one  in 
Fig.  96.  It  cuts,  spreads,  and 
twists  the  wicks  in  one  opera- 
tion and  quite  rapidly ;  its  mode 
of  working  is  very  simple.  A 
is  the  body  of  the  machine,  in 


the  interior  of  which  are  the 
pulleys  that  regulate  the  movement  of  the  carriage  worked 
by  the  treadle  (7,  a  framework  with  a  range  of  boxes  for  the 
balls  of  wick,  one  end  of  which  runs  through  a  notched  reel 
below  and  comes  forward  upon  the  twisting  board 
which  has  in  its  back  edg-e  a  knife  serving  as  the  under  blade 
of  the  movable  clipper  D.  This,  when  drawn  down  verti- 
cally, severs  the  wicks  evenly.  Tiie  twisting  box  E  C  con- 
sists of  two  boards  hinged,  and  moving  on  rollers.  A  turn 
of  the  crank  near  the  end  twists  the  wicks  after  they  have 
been  cut  by  the  knife  E^  which  having  effected  its  purpose 
is  drawn  up  again  by  a  counterpoise  F.  At  the  front  is  a 
sliding  board  so  fixed  that  it  can  regulate  the  length  of  the 
wicks. 

Another  wick  cutter  is  well  represented  by  Fig.  97.  The 
wicks  are  rolled  on  spools  which  are  placed  in  the  drawer  at 

upon  which  they  are  produced  has  a  circumference  of  1^  yards,  or  54  inches 
English  measure.  80  threads  form  a  lea  or  wrap,  seven  of  which  go  to 
one  hank  (number  or  skein),  hence  the  hank  has  a  thread  length  of  54  by 
560  English  inches,  or  2520  English  feet.  The  number  of  the  yarn  indicates 
the  number  of  such  hanks  which  make  an  English  pound  weight.  No.  16 
or  40  is  therefore  yarn  whereof  16  or  40  hanks  weigh  1  pound.  In  Austria 
and  France  other  modes  of  numbering  are  in  vogue ;  the  numbers  of  an 
equal  fineness  according  to  the  Austrian  system  are  obtained  by  dividing  the 
English  number  with  1.22,  and  that  of  the  French  mode  of  designating 
when  the  English  number  is  divided  by  1.18. — Bolley  on  Illumination. 


MANUFACTURE  OF  CANDLES. 


491 


Fig.  96. 


the  rear.  The  ends  are  drawn  over  a  rod  and  adjusted  to 
the  proper  length  ;  the  knife  is  drawn  down  and  cuts  evenly 
a  whole  range  of  wicks,  a  motion  of  the  machine  giving  at 


492  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


the  same  time  a  slight  twist.  The  rod  is  then  removed  and 
replaced  by  an  empty  one  to  be  in  turn  filled. 

In  order  to  combine  the  soaking  of  the  wick  end  with  the 
operations  of  cutting,  an  apparatus  which  we  delineate  in  the 
Figs.  98,  99,  and  100  is  used.    Fig.  98  is  a  vertical  section, 


Fig.  98. 


and  Fig.  99  the  ground  plan  of  the  apparatus ;  c  c  are  spools 
upon  which  the  wicks  are  rolled ;  b  a  roller  into  wiiich  cir- 


Fig.  99. 


cular  gutters  are  cut,  through  which  the  wicks  are  intro- 
duced into  the  clamp  6?,  and  by  which  they  are  kept  together. 
Fig.  100  represents  the  clamp  on  an  enlarged  scale  in  a  side 
view;  it  consists  of  two  side  bands,  d  and  (/,  which  toward 
the  centre  are  somewhat  thicker.  On  each  side  a  steel  spring 
is  aflaxed,  which  keeps  the  bands  somewhat  apart  from  each 
other,  and  a  ring  through  which,  when  it  is  moved  to- 
wards the  centre,  the  bands  can  be  brought  near.    If  the 


MANUFACTURE  OF  CANDLES. 


493 


wick  ends  are  to  be  kept  together  between  the  two  bands, 
the  rings  must  be  pushed  towards  the  centre.  By  taking  the 
wicks  out  or  placing  them  in,  they  are  pressed  towards  the 
end.  In  the  rear  of  this  clamp  is  a  cutting  apparatus,  con- 
Fig.  100. 


sisting  of  a  stationary  blade  /,  and  a  knife  /  which  has  a 
handle  moving  on  hinges ;  ^  is  a  small  trough  filled  with 
liquid  fat  (which  may  be  kept  in  a  fluid  state  by  steam),  and 
finally  i  a  band  resting  upon  the  table  h. 

The  application  of  the  apparatus  is  as  follows :  The  wick 
ends  wound  ofl:'  from  the  spools,  are  stuck  into  the  clamp  dy 
the  rings  upon  them  closed  so  that  the  wicks  are  all  kept 
together.  The  movable  blade  /  of  the  cutting  apparatus  is 
lifted  up,  and  all  of  the  wick  ends  which  hang  upon  the 
clamp  are  moved  backwards  to  the  trough  dipping  the 
projecting  ends  of  the  same  into  the  hot  fat.  This  being 
done,  the  dipped  ends  are  fastened  by  means  of  the  band 

either  by  pressing  upon  the  still  soft  fat,  or  by  placing 
weights  upon  them  and  laying  them  upon  the  table.  The 
opened  clamp  d  is  then  carried  back  to  its  place,  again 
closed  and  the  blade /grasped  by  the  handle,  led  down  to- 
wards the  sharp  edge/,  and  thus  all  the  wicks  cut  off  to  an 
equal  length,  whereupon  the  entire  operation  is  commenced 
anew. 

A  great  many  devices  in  plaiting  and  gimping  of  wicks 
have  been  patented  and  used,  but  it  has  narrowed  down  to 
the  simple  plaiting  for  nearly  all  moulded  candles  and  the 
coarse  twisted  for  dipped  candles.  Of  course  the  wicks  are 
made  of  a  size  suitable  to  the  diameter  of  the  candle. 


494  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


SECTION"  Y. 


THE  MANUFACTURE  OF  CANDLES  (Continued). 


Dipped  Candles. 

Dipped  candles,  though  rapidly  dying  out,  are  still  made 
where  tallow  is  abundant  and  large  factories  are  remote,  and  in 
new  countries,  and  the}^  therefore  should  be  properly  described 
by  us.  They  are  always  made  of  tallow  more  or  less  purified 
and  hardened  by  processes  we  have  already  described,  and 
assisted  by  apparatus  that  are  here  illustrated.  Dipping  by 
hand  is  accomplished  without  much  help  from  machinery, 
which  is  of  the  simplest  kind.  The  melted  tallow  is  placed 
in  a  dipping  trough  ;  its  length  is  about  three  feet,  its  height 
two  feet,  and  its  width  twelve  to  eighteen  inches ;  it  should 
have  handles  or  be  on  wheels,  for  convenience  in  moving;  the 
edges  incline  slightly  inward  that  the  suet  may  run  back 
into  the  melted  fat. 

On  commencing  operations  the  workman  takes  10  or  12 
rods  strung  with  wicks  as  shown  in  Fig.  101,  and  dips  each 


Fiff.  101. 


Fig.  102. 


tri 


in  the  liquid  fat  to  let  them  be  thoroughly  soaked;  for  this 
purpose  the  tallow  is  quite  hot,  that  it  may  be  completely 
absorbed  by  the  wick  ;  he  then  places  them  upon  the  frame 
Fig.  102,  which  is  a  strong  framework  of  wood,  the  rods 


MANUFACTURE  OF  CANDLES. 


495 


being  passed  upon  the  cross-pieces  ah  c.  When  the  wicks 
have  cooled  sufficiently,  they  are  again  dipped  into  the 
tallow,  which  must  now  be  much  cooler,  that  it  may  adhere 
in  sufficient  quantity.  They  are  again  cooled  and  again 
dipped  until  sufficient  tallow  has  adhered  to  form  the  desired 
size  of  the  candle,  which  is  regulated  by  a  weight.  The 
number  of  times  necessary  to  dip  a  candle  is  governed  by  the 
fluidity  of  the  fat.  All  the  manipulations,  though  simple, 
^require  skill  and  practice. 

Dipped  candles  are  seldom  symmetrical,  but  often  quite 
unequal  in  appearance ;  to  obviate  this  a  drawing  plate  is 
often  used.    Fig.  108  is  made  of  hard  wood  twelve  inches 

Fig.  103. 

IqqoqqqqqooI 

long,  two  or  three  inches  wide,  and  about  three-quarters  of 
an  inch  thick,  in  which  are  merely  bored  a  number  of  holes  of 
sizes  required  for  the  sizes  of  the  candles.  The  holes  are  graded 
from  large  to  small,  the  last  being  the  size  required  for  the 
finished  candle.  The  holes  have  a  slight  bevel  that  the  cutting 
edge  may  be  the  sharper,  and  that  the  candles  may  be  the 
easier  run  through.  The  workmen  draw  the  candles  first 
through  the  larger  hole  which  takes  oft'  a  portion,  then 
through  a  smaller  one  which  removes  more,  and  so  on  until 
the  desired  size  is  obtained  for  the  finished  candle.  This 
operation  improves  the  appearance  as  well  as  the  burning  of 
the  candle. 

To  facilitate  the  dipping  of  candles  many  ingenious  ma- 
chines are  in  use.  Figs.  104,  105,  106,  107, 108  show  one 
much  used.  In  this  machine  the  rods  loaded  with  wicks 
are  arranged  in  a  movable  frame,  suspended  by  cords  over 
the  vessels  or  baths,  one  inserted  within  the  other.  The 
larger  or  outer  bath  with  its  charge  of  tallow  is  kept  warm 
by  the  furnace  (Fig.  109),  from  32.2°  to  35°  C.  (90°  to  95°  F.), 
so  that  the  inner  bath  heated  by  it  may  have  a  temperature 


496 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


of  12.7°  to  15.5°  C.  (55°  to  60°  F.).  A  workman  lowers  and 
raises  each  frame  alternately  with  the  hand,  thus  dipping  and 
re-dipping  the  candles  until  they  attain  their  proper  size. 


The  framework  consists  of  five  oaken  beams  a,  Figs.  104, 
105,  the  end  bearing  two  abutments  b  connected  by  the  cross- 


MANUFACTURE  OF  CANDLES. 


497 


piece  throughout  the  length  of  which  are  five  small  trusses, 
into  each  of  which  is  tennoned  and  mortised  one  of  the 


Fig.  106. 


Fig.  107.  Fig.  108. 


heams  a.  The  iron  caps  dd  are  fixed  upon  the  sides  of  the 
long  crosspiece  of  the  frame  c ;  each  has  two  brass  pulleys ; 
the  fastening  of  one  of  these  caps  is  shown  in  front  view  and 
profile.  Through  each  pulley  runs  a  cord  /,  at  the  end  of 
which  is  suspended  a  small  wooden  frame  grooved  for  the 
reception  of  the  rod  g  which  carries  the  candle-wicks.  The 
wooden  handles  g g  have  each  a  hook  fastened  in  a  hole  in 
the  centre  of  a  small  rectangular  iron  plate  ^,  to  which  are 
attached  the  cords  of  the  pulleys  and  the  frame  e. 

32 


498 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


The  lono^  traverse  h  is  grooved  on  each  side  to  facilitate  the 
movements  of  the  furnace  seen  in  the  vertical  cut  (Fig.  105). 


Fig.  109. 


This  furnace  (Fig.  109)  rests  on  four  casters  so  that  its  position 
can  be  changed,  and  it  has  doorways  for  the  small  furnace  I  for 
maintaining  the  fusion  of  the  tallow  contained  in  the  larger 
vessel.  This  tallow,  kept  at  a  temperature  of  32.2°  to  35°  C. 
(90°  to  95°  F.),  imparts  sufficient  heat  to  the  contents  of  the 
smaller  bath  to  insure  the  adherence  of  the  tallow  to  the  can- 
dles each  time  they  are  dipped.  Upon  the  ledge  of  the 
larger  basin  is  an  iron  drainer^,  upon  which  the  dripping 
from  the  candles  is  caught.  The  furnace  is  fed  by  currents 
of  air  admitted  through  the  draughtway  q ;  it  has  crockets  r 
that  work  in  the  groove  of  the  crosspiece  h  which  serves  to 
conduct  the  furnace  from  one  frame  of  candles  to  another. 

The  mode  of  operating  this  machine  is  easily  understood: 
when  the  candles  have  been  dipped  sufficiently,  the  frame  is 
raised  and  left  suspended  by  fastening  the  hook  of  the  handle 

into  the  centre  of  the  piece  z,  and  while  they  are  hardening 
the  furnace  is  pushed  to  the  succeeding  frame.  This  machine 
works  rapidly,  and  the  work  is  uniform. 

J'he  Edinburgh  wheel  is  an  apparatus  much  used  in  this  art, 
and  is  shown  in  Fig.  110.    A  A  is  the  strong  upright  post, 


MANUFACTURE  OF  CANDLES. 


499 


which  turns  upon  pivots  at  its  two  ends.  i^ear  its  middle 
six  mortises  are  cut,  into  each  of  which  a  long  bar  of  wood  B  B, 


Fig.  110. 


which  moves  vertically  upon  an  iron  pin,  also  passes  through 
the  middle  of  the  shaft ;  the  whole  presenting  the  appearance 
of  a  long  horizontal  wheel  with  twelve  arms.  From  the  ex- 
tremity of  each  arm  is  suspended  a  frame  or  ''post"  containing 
six  or  more  rods  or  "baguettes"  containing  the  wicks.  The 
machine,  though  heavy,  turns  by  the  smallest  effort,  and  each 
post  as  it  comes  in  succession  over  the  bath  of  tallow  is  gently 
pressed  downwards,  and  the  wicks  immersed.  In  order  to 
prevent  oscillation,  the  levers  are  kept  horizontal  by  small 
chains  aa^  the  ends  of  which  are  fixed  to  the  top  of  the  upright 
shaft,  and  the  other  terminates  in  a  small  square  piece  of 
wood  b  which  exactly  fills  the  notch  c  in  the  lever.  As  a 
lever  must  be  depressed  at  each  dip,  the  square  piece  of  wood 
is  thrown  out  of  the  notch,  and  that  it  may  recover  its  posi- 
tion on  raising  the  post,  a  small  cord  is  connected  with  a 
pulley,  and  the  weight  draws  it  back  again  to  the  notch.  In 
this  manner  the  dipping  can  be  conducted  with  regularity 
and  dispatch.  The  candles  are  assisted  in  cooling  by  being 
in  constant  motion  in  the  air,  thus  completing  from  9,000  to 
15,000  per  day. 


500 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


Another  very  useful  machine  for  dipping  candles,  which 
makes  msiuy  thousand  candles  in  an  operation,  is  very  well 
shown  in  Fig.  111.    Forty  frames  each  containing  thirty 


loaded  rods  may  be  suspended  on  this  machine.  The  frames 
are  brought,  one  after  the  other,  to  the  vessel  of  tallow  and 
dipped.  By  means  of  a  lever  moved  by  the  foot  a  wiping 
board  is  lowered  after  each  dipping,  which  removes  the  ex- 
cess of  tallow  from  the  ends  of  the  candles.  A  kind  of 
balance  to  which  each  frame  is  in  turn  attached,  shows  the 
weight  of  the  candles.  When  by  dipping  they  are  of  suffi- 
cient weight,  they  are  set  aside  to  harden  and  dry. 

From  these  descriptions  the  manufacturer  should  receive 
sufficient  instructions  for  tlie  dipping  of  candles,  though,  from 
the  great  improvements  in  making  moulded  candles,  which 
are  much  handsomer,  dipped  candles  are  not  much  used  at 
the  present  time. 


Fig.  111. 


MANUFACTURE  OF  CANDLES. 


501 


SECTIO^T  YI. 
THE  MANUFACTURE  OF  CANDLES  (Continued). 

Moulded  Candles. 

Moulded  candles  are  much  more  sightly,  and  are  usually 
made  of  better  materials  than  dipped  candles;  moreover,  the 

Fig.  112.  Fig.  113.  Figs.  114,  115. 


Operation  of  moulding  is  simpler  and  more  expeditious,  and 
moulding  is  the  manner  in  which  nearly  all  candles  of  the 


502 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


better  class  are  made,  and  by  numerous  ingenious  machines 
that  greatly  facilitate  the  process. 

The  moulds  are  usually  made  of  pewter  (lead  and  tin) ; 
those  for  stearic  acid  candles  are  made  of  tin  and  antimony, 
and  are  thinner.  They  vary  somewhat  in  form  ;  the  French  ' 
moulds  are  shown  by  Figs.  112,  113,  114,  115.  Each  mould 
consists  of  two  parts,  the  body  and  the  head  piece,  as  shown 
by  Fig.  112;  the  shaft  a  a  is  widened  on  top  for  the  reception 
of  the  cap  m,  of  the  head  piece  d.  Fig.  113  shows  the  two 
pieces  united.  Fig.  114  shows  the  position  of  the  wick  held 
by  the  small  hook  ?i,  which  is  exactly  in  the  centre  of  the 
mould.  The  moulds  are  bored  out  by  machinery,  so  that 
the  interior  shall  be  perfectly  true,  and  finely  polished. 


Fig.  116. 


The  moulds  made  in  this  country  are  of  a  better  form,  as 
seen  in  the  Fig.  116,  which  represents  the  candles  made  in 
them.  They  are  burnished  y  a  vertical  instead  of  a  rotary 
motion,  which  makes  the  candles  easier  to  remove.  They 


MANUFACTURE  OF  CANDLES. 


503 


consist  of  two  pieces,  the  shaft  and  the  tip,  the  latter  being 
sometimes  made  of  brass,  or  washed  with  brass,  to  resist  the 
abrasive  effects  of  the  wick  and  pegs.  The  alloy  for  these 
moulds  is  tin  and  lead,  with  only  sufficient  of  the  latter  to 
render  them  smoother  and  easier  to  work. 

Moulding  by  hand  is  still  conducted  in  small  towns  and 
factories,  and  is  rather  a  simple  process.  Melting  kettles  for 
this  purpose  are  the  ordinary  kettles  set  in  brickwork  as 
shown  in  Fig.  117,  with  tub,  strainer  and  can.  Fig.  118. 
Fig.  119  represents  a  convenient  mould  stand,  now  much  in 


Fig.  119. 


use.  A  A,  two  upright  ends  supporting  the  cross-beds  B  B, 
that  hold  the  moulds;  the  upper  bed  is  of  metal.  CO  are 
broad  side  pans  which  form  a  receptacle  for  the  tallow  when 
the  moulds  are  being  filled,  one  side  of  which  can  be  removed 
with  convenience  in  working,  and  shows  the  wires  that  sus- 
pend the  wicks. 

The  threading  needle  is  shown  by  Fig.  115;  it  is  of  iron, 
and  has  a  slight  catch  for  holding  the  wick  ;  it  is  used  by 
holding  it  in  the  right  hand,  while  in  the  left  are  held  the 
wicks.  The  needle  passing  through  the  mould  appears  at  the 
loop  in  the  tip,  when  the  wick  is  caught  by  the  catch  in  the 
needle  and  pulled  through,  when  the  wire  of  the  mould- 


504 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


stand  passing  through  the  loops  holds  the  wicks  in  position. 
A  small  wooden  peg  is  often  put  in  the  hole,  which  seems  to 
hold  the  wick  tight  and  prevent  the  melted  tallow  from 
leaking  out. 

The  frames  being  in  readiness  and  the  tallow  at  the  proper 
temperature,  the  moulds  are  filled  with  the  same.  To  succeed 
well,  care  must  be  taken  to  have  the  tallow  neither  too  hot  nor 
too  cold.  If  too  hot,  it  hurts  the  mould  and  causes  the  can- 
dles to  adhere  and  he  full  of  cracks.  If  too  cold,  the  candles 
have  a  granular  structure  and  look  uneven  ;  in  the  first  case, 
the  candles  are  removed  by  dousing  the  moulds  in  warm 
water  after  they  have  cooled  and  the  candles  dexterously 
drawn  out.  The  proper  heat  for  the  tallow  is  when  on  cooling 
a  pellicle  forms  on  the  sides  of  the  kettle,  at  a  temperature  of 
about  37.7°  to  44.4°  C.  (100°  to  112°  F.).  The  mould  while 
cooling  should  be  left  in  quiet  in  an  upright  position,  and  the 
wick  ends  showing  below^  the  tip  are  straightened  by  pull- 
ing before  the  candle  congeals,  unless  the  pegs  spoken  of  have 
held  the  wicks  firmly  in  position.  When  the  moulds  have 
caps,  the  candles  are  easily  drawn  by  raising  the  caps  and 
cutting  them  at  the  junction,  otherwise  the  workman  presses 
his  thumb  against  the  bottom  of  each  candle  to  loosen  it, 
and  draws  it  with  a  kind  of  bodkin. 

When  first  made  from  ordinary  materials,  the  candles  are 
more  or  less  yellowish,  and  it  is  customary  to  expose  them  to 
light  and  air,  which  bleaches  them  somewhat,  but  if  packed 
away  the  color  returns.  The  best  remedy  is  to  have  the 
tallow  whitened  by  some  of  the  processes  we  have  described 
in  a  previous  section.  It  is  true  that  they  will  become  white 
with  age,  but  it  is  by  absorbing  oxygen  and  becoming  rancid 
unless  kept  from  the  air. 

Moulding  by  machinery  has  nearly  superseded  the  more 
tedious  method  by  hand,  and  there  are  numerous  mechani- 
cal appliances  more  or  less  perfect  and  rapid,  for  small  as 
well  as  large  manufactories.  If  the  article  to  be  moulded  be 
tallow,  it  is  preferable  to  have  it  hardened  and  bleached.  The 
hardening  is  done  by  pressing  out  a  portion  of  its  oil,  or  by 
granulating  and  separating  as  previously  described. 


MANUFACTURE  OF  CANDLES. 


505 


In  the  melting  and  refining  of  the  tallows,  steam  is  now 
generally  employed,  particularly  when  a  large  quantity  is 
needed  for  moulding  by  machinery.  We  here  illustrate  a 
convenient  form  of  apparatus  for  melting,  Fig.  120.  The 


steam  generator  A.  The  reservoir  B  contains  the  water  for 
feeding  the  boiler  by  the  cock  ^N";  the  draft  is  regulated  by  the 
damper  G.    The  boiling  tubs  C  C  C  are  heated  by  the  pipe 


506  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

0  0  0.  This  range  of  melters  is  convenient,  as  a  constant 
supply  of  melted  fat  can  be  kept  up. 

.  LeuheVs  moulding  machine  is  arranged  to  make  396  can- 
dles at  one  operation.    Fig.  121  shows  a  front  elevation  of 


Fig.  121. 


one-half  of  the  machine,  also  the  moulds.  The  moulds  are 
ranged  in  a  stand  somewhat  like  the  ordinary  one,  on  top  ot 
which  is  a  second  stand  but  ledged  and  made  of  iron  or 
other  metal  and  pierced  with  holes  corresponding  with  those 
in  the  wooden  stand  beneath.  In  each  of  these  holes  is 
lodged  a  kind  of  small  funnel,  to  which  is  attached  the  wick 
which  descends  into  the  moulds.  The  metallic  stand  is  so 
arranged  that,  by  the  aid  of  a  winch  moving  a  cogged  rack, 
it  can  be  raised  or  lowered  at  will.  When  the  candles  are 
about  to  be  cast,  the  metal  stand  is  lowered  until  the  funnel 
caps  touch  in  the  top  of  the  moulds,  w^hen  the  fluid  tallow 
being  poured  upon  this  stand  runs  through  the  caps  into  the 
396  moulds.  After  perfect  congelation  the  metallic  plate  is 
raised  by  the  winch  and  the  candles  severed  with  a  long 
knife.  In  warm  weather  the  moulds  are  cooled  in  a  vessel 
of  ice-water,  elevated  so  that  the  filled  moulds  are  dipped 
their  whole  length  in  it.  A  is  the  framework  of  oak  wood ; 
the  platform  d  supports  the  vessel  e  of  water  for  cooling 
the  moulds.    The  metallic  table  fis  pierced  with  holes  cor- 


MANUFACTURE  OF  CANDLES. 


507 


responding  in  size  and  position  with  those  in  the  wooden 
tabled.  Figs.  122  and  123  show  other  views  of  this  machine  ; 
Fig.  124  the  arrangement  of  the  wick. 


The  manner  of  working  this  machine  is  to  commence  by 
placing  the  moulds  in  the  holes  of  the  wooden  stand  and 
the  funnel  caps  in  those  of  the  metallic  stand/,  which  being 
done,  the  upper  stand  is  lowered  by  the  winch  m,  until  the 
caps  get  into  the  ends  of  the  moulds.  The  wicks  are  arranged 
in  the  usual  manner,  and  retained  in  position  by  hooks  in 
the  centre  of  each  cap ;  when  all  is  ready  the  melted  tallow 
is  poured  in  upon  the  table/,  whence  it  runs  into  all  the 
moulds. 

When  the  candles  have  cooled  and  hardened  in  cold  weatber 
by  the  atmosphere  or  in  warm  weather  by  the  bath  of  ice- 
water,  the  metal  table  to  which  the  candles  adhere  is  lifted 
up  and  the  candles  are  detached  with  a  knife.  The  opera- 
tion being  finished,  the  caps  are  removed  and  cleansed  in  hot 
water  before  using  again.  The  moulding  is  facilitated  by 
having  the  upper  metallic  frame  warmed  sufficiently  to  pre- 
vent the  too  rapid  cooling  of  tbe  fat ;  being  larger  than  the 


508  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


lower  frame,  it  can  be  heated  with  a  tin  box  running  along 
its  edge  filled  with  hot  water  or  steam. 

Morgan's  moulding  machine,  used  in  England  for  tallow 
candles,  is  so  constructed  that,  with  a  sufficient  number  of 


Fig.  125. 


Fig.  126. 


stands,  the  moulding  can  be  continued  for  an  indefinite 
period,  and  at  a  saving  of  labor  and  time.    The  wicks  in  this 


Fig.  127. 


i 

III 

e  e 

d  d 

G 

Fig.  128. 


Fig.  129. 


MANUFACTURE  OF  CANDLES. 


509 


Fig.  130. 


machine  are  threaded  through  the  moulds  at  the  same  time 
and  hy  the  same  action  as  that  which  expels  the  candles. 
Fig.  125  shows  the  end  elevation,  and  Fig.  126  a  front  view ; 
Fig.  127  the  plan,  and  Fig.  128  the  elevation  of  the  back 
opposite  Fig.  126.  A  represents  the  vessel  or  reservoir  con- 
taining the  fat;  B,  a  series  of  moulds.  Fig.  129,  the  range 
of  moulds  constructed  in  a  peculiar  manner.  Fig.  130  shows 
the  upper  end  of  one  of  these  moulds,  and  Fig.  131  a  plan  view 
of  the  same ;  it  will  be  here  seen  that  the  top 
is  in  several  pieces.  6  1  is  a  portion  of  the 
cylindrical  side  of  the  mould;  b  2,  the  mov- 
able portion.  This  latter  6  2  is  hollow  for  the 
passage  of  the  wicks,  and  fits  closely  to  b  1, 
when  the  tallow  is  poured  in.  But  as  soon  as 
the  candle  is  cold,  and  in  a  condition  to  be  re- 
moved, instead  of  being  drawn  out  in  the  usual 
way  it  is  by  this  apparatus  forced  out  by 
pressure  applied  to  the  extremity  of  the  part 
b  2  following  the  course  of  the  candle  as  it  is 
forced  from  the  mould,  rewicking  the  mould  for  another 
candle.  In  Fig.  129  is  shown  a  hollow  cylinder  of  tin,  bb, 
holding  the  bobbins  of  wnck  revolving  on  a  shaft  passing 
through  its  length.    Fig.  132  exhibits  a  series  of  nippers 


Fig.  131, 


Fig.  132. 


opening  and  shutting  by  the  action  of  the  lever  holding 
the  wicks  (at  the  end  opposite  to  that  of  its  entrance)  in  b  2 
in  a  perpendicular  position. 

To  work  this  apparatus  we  suppose  a  frame  of  moulds  B 
regularly  wicked  and  in  the  position  shown  at  B^,  Figs.  126, 
127,  128,  where  the  case  is  supported  perpendicularly  on  the 
small  straight  edges  of  a  railway  dd.  Fig.  127.  In  this  position 
they  are  run  forward  until  they  come  under  the  reservoir  A, 
when  the  tallow  is  applied  in  the  usual  manner.  The  moulds, 
being  tilled,  are  run  abng  the  railway  dd  to  harden.  When 


510  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


the  candles  have  perfectly  congealed,  the  moulds  are  brought 
to  the  position  shown  at  B  (Fig.  127),  when  they  are  placed 
on  a  railway  similar  to  that  shown  at  dd  on  the  other  side  of 
the  machine.  Here  they  are  pushed  forward  until  they  arrive 
at  the  hanging  table  D  which  vibrates  on  the  joint  ee,  and  is 
then  let  down,  but  immediately  returned  to  the  longitudinal 
position  given  at  D,  Fig.  127.  The  moulds  B  are  moved  until 
they  arrive  at  the  series  of  rammers  E,  as  separately  shown 
in  Fig.  134,  where  the  cylindrical  case  6  6  is  removed  by  turn- 


Fig.  133. 


Fig.  134. 


Fig.  135. 


ing  the  jointed  frame,  as  seen  in  Fig.  135,  to  be  out  of  the 
way  of  the  rammer  E.  This  series  of  rammers  E,  moves 
freely  in  a  horizontal  direction  supported  on  straight  edges 
at  each  extremity,  and  is  moved  by  the  partial  rotation  of 
the  wheel  C,  as  shown  in  Fig.  125,  where/ shows  a  band  or 
chain  passing  over  its  periphery,  and  round  the  guide  pulley 
fK  This  chain  or  band  /  is  attached  to  a  series  of  rammers 
E,  so  that  the  pressing  of  the  lever  which  is  fixed  on  the 
axis  of  the  wheel  C  imparts  motion  to  the  rammers  E  in  a 
horizontal  direction.  The  moulds  being  in  the  position 
shown  at  Fig.  135,  the  next  thing  to  do  is  to  bend  down 
the  lever  c\  thereby  forcing  the  series  of  rammers  E  into  con- 
tact with  the  sliding  part,  6^,  of  each  of  the  moulds,  and 
thereby  pushing  out  the  candles  which  are  received  into  the 
grooved  table  F,  raised  up  in  exact  position  to  receive  them 


MANUFACTURE  OF  CANDLES, 


511 


by  tlie  action  of  the  scroll-piece  c^,  attached  to  the  wheel  C, 
and  on  which  the  grooved  table  F  is  supported.  The  candles, 
being  forced  from  the  moulds  by  the  rammers,  are  immedi- 
ately secured  and  held  stationary  by  depressing  the  lever  G, 
which  is  provided  with  a  series  of  like  number  of  small  con- 
vex pieces  of  pewter,  formed  of  a  section  of  the  candle 
moulds,  which  are  attached  to  slight  springs,  as  seen  in  Fig. 
126.  The  lever  is  held  dow^n  by  a  small  catch.  From  w^hat 
has  been  said  of  the  frame  of  moulds  B,  it  is  obvious  that 
the  same  action  of  the  rammers  E,  which  displaces  the  can- 
dles, will  carry  down  to  the  moulds  a  fresh  supply  of  wicks 
for  the  succeeding  candles,  and,  at  this  period,  while  the 
finished  candles  are  secured  on  the  table  F,  the  nipper  /, 
shown  at  Fig.  132,  must  be  reapplied,  after  which  the  fin- 
ished candles  are  cut  ofi:'  and  disposed  of. 

The  next  duty  of  the  operator  is  to  replace  the  lever  c\  in 
the  position  shown  at  Fig.  125,  which  carries  back  the  ram- 
mer E  along  with  the  sliding  top  of  the  moulds  26,  to  their 
former  position,  and  the  moulds  are  wicked  ready  for  a  fresh 
supply  of  tallow.  This  series  of  rammers  E,  is  formed  of 
separate  hollow  tubes,  supported  in  the  cross-piece  gg^  each 
of  which  tubes  is  provided  with  a  small  spring  having  a 
slight  projection  on  its  inside  by  means  of  which  when  the 
rammers  are  pressed  against  the  sliding  part  of  the  moulds, 
marked  26,  the  spring  gives  way  and  catches  firm  hold  of  the 
notched  part  as  shown  at  Fig.  130,  and  is  thereby  enabled  to 
bring  it  back  to  its  former  position,  where  the  candles  are 
forced  from  the  moulds  as  soon  as  the  rammers  are  retired, 
and  have  brought  back  the  sliding  tops  26  of  the  respective 
moulds  ;  the  springs  at  their  extremity,  which  had  held  the 
26,  are  relieved  or  lifted  up  by  a  second  series  of  rammers 
or  rods,  which  pass  up  the  interior  of  the  hollow  rammers,  as 
already  described.  This  second  series  of  rods  is  fixed  in  a 
similar  cross-piece  marked  AA,  in  Fig.  127,  which  as  soon  as 
the  rammers  are  retired  from  the  moulds,  is  forced  forwards 
by  means  of  the  lever  II,  and  thereby  the  caps  26,  and  the 
w^hole  of  the  moulds  marked  B,  freed  from  any  connection 
with  the  rammers  E.    At  this  period  the  moulds  are  passed 


512  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


forward  to  the  railroad  dd^  and  replaced  in  the  position 
shown  at  ;  the  tallow  from  the  receiver  A,  again  supplied 
to  them,  and  the  process  already  described,  repeated  any  num- 
ber of  times.  This  description  is  elaborate,  and  judging  by 
it  the  machine  may  seem  complicated,  but  it  is  not  so,  the 
working  is  quite  simple  and  rapid. 

Improved  Continuous  Wick  Machine. — The  latest  improve- 
ment in  this  useful  machine  is  here  shown.  Fig.  136,  ap- 
plicable to  tallow  as  well  as  to  stearic  acid  or  paraffin  candles. 
The  moulds,  one  hundred  in  number,  are  inclosed  in  the  cast- 


Fig.  136. 


iron  box  a ;  these  moulds  are  tubes  open  at  each  end.  The 
tip  forming  the  top  of  the  candle  is  fastened  to  a  tube  of  iron 
through  which  the  wick  passes ;  these  tubes  are  fastened  to 
the  platform  which  is  connected  by  a  rack  and  pinion 


MANUFACTURE  OF  CANDLES. 


518 


moved  by  the  crank  g.  The  wicks  are  reeled  on  bobbins  in- 
closed ill  the  lower  case.  Above  the  mould  case  is  placed  an 
apparatus  called  a  nipper,  which  o;rasps  the  finished  candles 
as  they  are  raised  out  of  the  moulds  by  the  piston  tubes. 
The  nipper  is  formed  of  hard  wood  lined  with  India-rubber 
and  acted  upon  by  means  of  hinges  and  cranks. 

To  the  mould  box  are  suitable  valves  for  the  admission  of 
hot  or  cold  water,  either  to  warm  the  moulds  or  cool  them 
and  the  candles.  This  machine  for  an  ordinary  business 
presents  many  advantage.-?,  as  with  proper  management  the 
moulding  can  be  continued  without  much  intermission. 

Ashley's  Mouldwg  Machine  has  a  device  to  impress  the 
trade-mark  or  initials  of  the  manufacturer  upon  the  candles 
during  the  process  of  moulding,  to  accomplish  which,  the 
moulds  are  arranged  in  the  stand  at  an  angle  of  fifteen 
degrees,  with  their  tips  uppermost.  Openings  are  made  in 
the  side  near  the  tips  for  the  passage  of  the  melted  tallow, 
wdiich  is  supplied  from  a  suitably  arranged  vessel.  There  is 
also  an  arrangement  for  making  the  wicks  continuous,  so 
that,  as  in  the  last  machine  described,  the  act  of  drawing 
one  batch  of  candles  simultaneously  wicks  the  moulds  for 
the  next  cutting.  When  the  tallow  is  about  to  "set"  in  the 
moulds,  stoppers  are  pressed  into  the  mouths  of  the  moulds, 
by  which  manipulation  the  candles  acquire  smoothness  on 
the  lower  end,  and  at  the  same  time  receive  the  impress  of 
the  trade- mark. 

Camp's  Moulding  Wheel. — This  machine  is  an  American 
invention,  and  is  suitable  for  an  extensive  business,  as  with 
it  a  single  workman  can  mould  a  thousand  pounds  of  candles 
in  a  day.  Its  construction  is  very  simple,  and  it  is  moreover 
easily  managed,  and  its  working  has  given  general  satisfac- 
tion throughout  the  United  States. 

It  consists  of  a  revolving  platform  or  horizontal  wheel 
Fig.  137,  suspended  by  means  of  iron  brace-rods  0,  which 
centre  at  Z),  in  an  upright  shaft  turning  upon  its  pivoted 
ends  in  sockets  affixed  to  the  floor  and  ceiling  C.  The  plat- 
form serves  as  a  table  for  the  support  of  the  mould-slabs  ^, 
which  are  made  with  lateral  recesses  6,  for  the  reception  of 
33 


514  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


ice  when  the  warm  weather  renders  its  use  necessary  for 
cooling  the  candles.  In  the  lower  part  of  the  stands,  and 
just  below  the  tips  of  the  moulds  are  the  spools  of  wick  cor- 


MANUFACTURE  OF  CANDLES. 


515 


responding  in  number  with  those  of  the  moulds  in  the  stand. 
At  the  outset  the  wicks  are  drawn  from  the  spools  through 
the  moulds  and  adjusted  in  the  usual  manner,  by  hand.  This 
being  done  and  the  platform  being  filled  with  stands  in 
regular  order,  the  moulding  is  commenced  by  opening  the 
mouth  valve  of  the  feeding  tube  immediately  adjoining 
the  melting  tub  i2,  from  which  it  is  supplied  with  the  fluid 
tallow.  The  first  stand  being  filled,  the  wheel  is  then  pushed 
around  till  the  next  stand  succeeds  to  its  place  under  the 
valve  of  the  feeder  and  is  filled  in  its  turn,  and  so  on,  the 
operation  proceeding  until  all  the  stands  are  filled.  Before, 
however,  the  last  stands  are  filled,  those  first  filled  will  have 
cooled,  enabling  the  operator  to  be  kept  constantly  at  work 
fi.lling  or  drawing  from  the  stands  the  solidified  candles,  or 
preparing  the  mould  stands  to  maintain  their  order  during 
the  revolution  of  the  wheel,  thus  making  the  process  rapid 
and  continuous.  The  whole  row  of  candles  is  drawn  simul- 
taneously, and  the  candles  are  laid  over  in  grooved  ruts,  cut 
in  the  ledges  of  the  stand  for  their  support.  As  the  wicks 
are  also  drawn  at  the  same  time,  it  follows  that  the  moulds 
are  threaded  for  the  succeeding  candles,  the  first  candle  is 
allowed  to  rest  in  the  groove  until  the  succeeding  candles 
have  cooled  when  it  is  cut  off  and  removed,  this  also  seems 
to  keep  the  wick  in  the  centre  of  the  moulds. 

Upon  this  very  useful  apparatus  there  have  been  several 
minor  improvements,  as  an  attachment  of  an  iron  cylinder 
to  the  feeder,  with  valves  to  admit  only  the  requisite  amount 
of  tallow  for  each  frame,  also  a  brake  on  each  frame  to  steady 
it  when  reaching  its  place  under  the  valve,  and  also  a  steam 
pipe  for  warming  the  moulds  in  very  cold  weather,  preventing 
a  too  rapid  cooling  which  causes  irregularity  in  the  appear- 
ance of  the  candle,  etc.  etc. 

Slearine  Candles. — Stearine  is  the  name  given  to  such  can- 
dles as  are  made  from  the  more  solid  parts  of  the  neutral 
fats.  We  have  described  the  partial  separation  of  the  olein 
in  our  section  on  dipped  candles,  yet  there  are  other  and 
more  elaborate  processes  for  making  them.  Lard  is  the  most 
desirable  base,  as  it  makes  with  suitable  care  a  beautiful 


516 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


white  candle.  We  have  made  these  candles  man}^  years  ago 
(1843),  in  the  west  where  lard  was  very  abundant  and  other 
means  of  lighting  scarcer  and  high  priced.  The  process  was 
comparatively  simple,  and  consisted  of  separating  the  oil 
by  pressure  through  deer  skin,  protected  with  canvas,  and 
melting  and  refining  the  stearine  or  harder  parts,  using  a 
portion  of  nitric  acid,  which  had  the  property  of  whitening 
and  hardening  the  fatty  body.  This  simple  process  con- 
ducted with  care  gave  at  that  time  a  satisfactory  candle. 

Braconnot,  a  French  chemist,  as  long  ago  as  1821  pointed 
out  the  affinity  of  some  of  the  hydrocarbons  for  the  olein  in 
the  fats,  and  his  hints  have  been  utilized  in  forming  a  good 
stearine  by  using  a  rectified  oil  of  turpentine  as  a  solvent  of 
the  more  fluid  parts.  The  process  as  followed  out  is  described 
thus:  Lard  or  tallow  is  melted  by  steam,  and  permitted  to 
cool  slowly  and  granulate,  and  it  is  then  pressed  to  expel 
the  oil  and  again  steamed  and  cooled  as  before,  and  pressed 
in  a  hydraulic  press. 

After  sufficient  pressing  the  cakes  of  fat  are  taken  out  and 
melted  in  a  jacketed  kettle  at  a  temperature  of  about  the 
boiling  point  of  water,  when  after  a  few  hours  heating,  the 
fat  is  allowed  to  rest  and  cool  to  about  48.9^  C.  (120°  F.), 
when  to  every  100  pounds  of  tlie  fat  are  added  while  con- 
stantly stirring  eight  pints  of  rectified  spirits  of  turpen- 
tine of  recent  distillation.  The  fat  thus  prepared  is  drawn 
off  into  tubs  and  allowed  to  rest  for  several  days  at  a 
temperature  of  about  10°  C.  (50°  F.),  when  it  will  have 
hardened  into  a  granular  mass,  which  is  again  pressed  in  a 
hydraulic  press,  using  a  gentle  pressure  at  first,  gradually 
increasing  it  until  the  utmost  is  used.  The  oil  that  exudes 
is  used  for  the  cheaper  kinds  of  soap.  When  thoroughly 
pressed  the  fat  is  removed  and  immediately  steamed  until  all 
trace  of  the  turpentine  is  dispelled,  the  water  is  drawn  off  and 
a  weak  solution  of  an  alkali  used  to  refine  it.  When  the  scum 
arises  and  is  removed  and  the  liquid  assumes  a  clear  aspect, 
it  is  finished,  and  is  now  strained  off  into  clean  tins,  and 
when  cool  should  have  a  beautiful  wax-like  appearance, 
especially  if  lard  has  been  the  body  operated  upon.    It  can 


MANUFACTURE  OF  CANDLES. 


517 


now  be  melted  and  moulded  in  the  manner  described  for  the 
best  tallow  or  stearic  acid  candles.  The  improved  continuous 
wick  machine  (Fig.  186,  page  512)  is  the  most  efficient,  as  by 
that  machine  the  moulds  can  be  warmed  or  cooled  for  mould- 
ing at  any  time  in  the  year. 

Moulding  Stearic  Acid  Candles. — Stearine  candles,  as  they  are 
called,  though  improperly,  as  the  term  stearine  seems  to  apply 
to  any  candle  harder  than  tallow;  stearic  acid  being  quite 
a  different  substance.  Some  attention  has  to  be  given  in  the 
preparation  of  the  wicks  for  stearic  acid  candles,  as  the  pure 
cotton  would  absorb  too  much  fat  and  burn  too  rapidly,  also  to 
keep  the  proportion  of  burning  wick  to  the  melted  matter 
constant,  as  well  as  to  adopt  those  wicks  which  in  burning  turn 
their  tops  out  of  the  flame  so  that  coming  in  contact  with 
the  air  outside  of  the  enveloping  curtain  of  the  flame  they 
are  reduced  to  ashes.  This  is  managed  by  so  plaiting  the 
wick  that  a  twist  is  given  to  it  which  causes  it  to  become 
unplaited  in  burning  and  twist  itself  out  of  the  flame.  The 
wick  is  composed  of  three  threads  (each  thread  having  a 
suitable  number  of  fine  ones),  one  thread  being  shorter  and 
thus  having  a  greater  strain  upon  it  than  the  others,  gives  a 
curvature  to  the  whole  point  as  soon  as  the  melting  of  the 
candle  allows  it  to  have  fair  play.  To  prevent  the  wicks 
burning  too  rapidly,  several  chemical  substances  are  used,  as 
muriate  of  ammonia,  phosphate  of  ammonia,  etc.,  but  we  have 
found  a  solution  of  boracic  acid,  one  ounce  to  one  gallon  of 
water,  adding  a  few  (say  twenty)  drops  of  sulphuric  acid,  to 
be  the  most  simple  and  efficient. 

Stearic  acid  crystal I  zes  very  rapidly  in  certain  temperatures, 
and  care  must  be  taken  to  prevent  it,  as  the  candles  would 
have  an  uneven  appearance  and  be  brittle.  To  remedy  this 
the  melted  acid  is  kept  agitated  while  cooling  and  put  into  the 
moulds  in  a  creamy  state;  this  is  very  much  assisted  by 
mixing  with  the  stearic  acid  about  10  to  20  per  cent,  of  pa- 
raffine,  but  even  with  this  addition  the  mixture  must  not  be 
moulded  until  it  looks  milky,  and  is  constantly  stirred. 
Wax  is  also  used  for  this  purpose,  but  it  is  more  expensive, 


518  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


while  the  paraffine  tends  to  make  the  candles  more  trans- 
parent. 

The  moulds  for  stearic  acid  candles  are  made  of  an  alloy  of 
one  part  tin  and  two  parts  lead,  and  in  some  instances  anti- 
mony is  added,  and  it  is  advisable  to  have  thinner  moulds 
than  those  used  for  tallow  candles ;  this  is  necessary  as  the 
moulds  are  warmed  and  cooled  rapidly  when  being  used. 
Moulds  of  glass  have  been  recommended,  but  they  have  not 
as  yet  found  much  favor,  though  it  would  seem  to  be  a  very 
suitable  material  for  them. 

Bleaching  the  Stearic  Acid. — This  process  may  be  necessary, 
as  it  is  seldom  sufficiently  white  for  moulding  when  first 
prepared.  If  the  stearic  acid  has  been  properly  washed  there 
is  but  little  to  do  in  further  preparation  for  moulding,  but  to 
melt  it  with  a  current  of  steam,  continuing  the  stirring  gently 
for  some  hours,  letting  it  rest  and  pouring  off  the  clear  acid 
into  pans,  taking  due  care  to  have  everything  free  from  dirt  of 
all  kinds.  Another  method  is  to  add  to  the  melted  acid  five 
per  cent,  of  sulphuric  acid  diluted  with  ten  per  cent,  of  water, 
and  stirring  as  before.  Again,  the  further  bleaching  is  pro- 
moted by  taking  off  the  above  acidulated  water,  adding  fresh 
water  and  the  whites  of  twenty-five  eggs  to  each  one  hundred 
pounds  of  fat,  the  steam  is  again  turned  on,  and  the  scum  of 
albumen  that  rises  skimmed  off; 

For  a  very  white  stearic  acid  we  have  found  that  nitric  acid 
is  a  very  efficient  agent ;  five  per  cent,  of  this  acid  is  added  to 
the  fat  previously  melted  by  steaming.  After  the  acid  has 
been  gradually  added  the  steam  is  shut  off,  but  the  agitation 
is  continued  with  a  twirl  or  by  constant  stirring  for  upwards 
of  an  hour,  when  being  left  to  repose,  the  acidulated  water 
is  drawn  off  and  the  stearic  acid  washed  several  times  with 
warm  water,  draining  ofif  the  water  of  each  washing.  The 
last  washing  is  accomplished  by  the  addition  of  steaming, 
and  when  finished,  the  clear  stratum  of  fat  is  ladled  oft*  into 
the  pans  to  cool. 

Moulding  stearic  acid  candles  hy  hand  is  but  seldom  adopt- 
ed except  in  very  small  factories,  yet  it  may  be  well  to 
give  some  details.    The  first  step  is  to  melt  the  stearic  acid 


MANUFACTURE  OF  CANDLES. 


519 


in  a  steam  jacket  similar  to  the  one  here  shown  (Fig.  138), 
from  whence  it  is  ladled  into  a  convenient  vessel  to  be  stirred 

Fig.  138. 


till  it  assumes  a  milky  appearance,  which  destroys  the  ten- 
dency to  crystallize,  and  assists  the  moulding.  In  the  mean 
time  the  moulder  is  gotten  read}^,  the  moulds  wicked  and 
arranged.    Figs.  139  and  140  show  an  iron  casing  where  the 


Fig.  139. 


moulds  are  made  warm  by  a  water  bath  and  the  steam  is  in- 
troduced by  a  perforated  pipe  running  on  the  bottom  and 
which  heats  the  water.  When  by  this  steaming  the  moulds 
are  warmed  to  the  proper  degree,  say  46°  to  49^  C.  (114.8°  to 


520 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


120.2^  F.),  the  stands  of  moulds  are  taken  out  and  imme- 
diately filled  with  the  milky  stearic  acid,  and  placed  where 


Fig  140. 


they  can  cool.  With  the  proper  precaution?,  the  candles  will 
be  of  uniform  appearance,  and  easily  draw^n  from  the  moulds. 
Fig.  141  is  a  jacketed  mould  stand,  useful  for  a  small  busi- 
ness, and  in  which  hot  and  cold  water  can  be  used. 


Fig.  141. 


Moulding  tnj  steam  has  so  many  advantages  that  the 
method  is  indispensable  to  large  operations.  For  this  purpose 
some  of  the  machines  already  described  may  be  employed, 
yet  there  are  several  in  use  by  the  French  manufacturers  that 
are  more  efficient.  We  illustrate  one  of  the  best.  Fig.  142 
represents  an  elevation,  A  A  being  the  case  for  the  bobbins  of 
wicks  in  number  corresponding  with  the  number  of  moulds. 
JBBis  another  case  of  plate  iron  called  the  heating  box,  into 
which  the  steam  enters  by  the  valve  C,  or  the  cold  air  by  the 
flue  Z),  having  a  suitable  register  E.    F  is  a  movable  carriage 


MANUFACTrEE  OF  CAKDLES. 


521 


running  on  four  wheels  upon  the  railway  G.  ^Ti? are  vertical 
racks  operated  by  the  toothed  wheels  /,  turned  by  the  crank  J". 
K  is  the  wick  holder  serving  to  keep  the  wick  in  position. 


522 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


To  operate  this  machine,  the  wicks  being  in  their  proper 
places,  the  steam  is  admitted  by  the  valve  C\  until  the  moulds 
are  sufficiently  heated,  when  it  is  turned  off.  Each  of  the  ten 
mould  stands  containing  eighty  moulds  fits  closely  into  its 
appropriate  place,  that  there  may  be  little  or  no  escape  of  steam 
or  air.  The  moulds  are  then  all  tilled,  when  the  register  E 
of  the  ventilator  D  is  opened  and  cold  air  forced  in  by  means 
of  a  blower,  and  when  the  candles  are  solid,  each  mould  stand 
is  emptied  by  means  of  the  hooks  grasping  the  wick  holder 
which  has  an  appliance  for  grasping  the  ends,  and  is  raised 
and  lowered  with  the  crank.  The  wicks  are  cut  with  a  suit- 
able knife,  and  the  carriage  brought  to  another  stand  and  so 
on  until  finished  ;  the  moulds  being  all  emptied,  the  operation 
can  be  resumed.  This  apparatus  is  designed  for  a  large  busi- 
ness, and  is  applicable  to  the  moulding  of  paraffine,  sperma- 
ceti, and  nearly  all  composite  candles. 

Faraffiyie  candles  may  be  considered  next  in  importance  to 
the  stearic  acid.  This  substance  is  found  in  nearly  all  mineral 
oils  and  as  a  by-product  in  the  preparation  of  coal  gas,  the 
refining  of  petroleum,  etc.  Paraffine  when  pure  is  a  white, 
wax-like,  tasteless,  and  odorless  substance,  having  a  fatty  ap- 
pearance. It  is  harder  than  tallow,  but  softer  than  wax ;  it 
has  various  melting  points,  ranging  from  43°  C.  (109.4°  F.) 
to  65.5°  C.  (150°  F.),  and  is  a  beautiful  material  for  candles, 
being  almost  transparent,  giving  a  clear  white  light. 

Moulding  Paraffine  Candles. — This  industry  has  but  few 
points  of  difterence  from  the  moulding  of  other  candles,  the 
moulds  being  the  same  as  for  stearic  acid  and  spermaceti, 
and  the  same  kind  of  plaited  wicks  are  also  used.  The 
principal  difterence  is  in  the  regulation  of  the  heat  in  mould- 
ing, the  moulds  being  heated  to  about  66°  C.  (150.8°  F.),  or  a 
little  above  the  melting  point  of  the  paraffine,  and  when  well 
filled  they  are  left  to  rest  a  few  moments  and  then  suddenly 
cooled  by  immersion  into  cold  water.  This  method  prevents 
their  crystallization  and  their  becoming  opaque,  instead  of 
the  natural  transparency  so  much  desired.  As  paraffine 
candles  are  apt  to  become  misshapen  and  bend  owing  to  their 
softening  below  their  melting  point,  it  is  customary  to  add 


MANUFACTURE  OF  CANDLES. 


523 


from  5  to  15  per  cent,  of  stearic  acid  to  them  ;  and,  again, 
paraffine  to  the  amount  of  15  to  20  per  cent,  is  added  to  the 
stearic  acid  candles  to  promote  their  good  appearance. 

Spermaceti  candles  are,  next  to  wax,  the  best  and  handsomest 
in  use,  giving  a  beautiful  white  light.  Spermaceti  before 
being  made  into  candles  has  to  be  very  pure,  and  the  process 
for  its  purification  has  been  elsewhere  described  more  in 
detail  than  we  can  do  here.  In  commerce  it  is  found  in  a 
sufficiently  pure  state  for  this  manufacture,  though  it  is  cus- 
tomary for  the  refiners  of  the  sperm  oil  to  also  purify  and 
mould  into  candles  the  spermaceti  so  extracted. 

Moulding  spermaceti  candles  can  be  done  in  almost  any  of 
the  moulding  machines  heretofore  described.  There  is  how- 
ever some  difference  in  the  manipulation,  as  it  is  customary 
to  mould  them  in  cold  weather,  heating  the  spermaceti  to 
about  the  boiling  point  of  w^ater,  running  it  into  the  moulds 
and  cooling  rapidly,  thus  keeping  them  transparent.  The 
apparatus  here  given  (Fig.  143)  is  one  made  especially 
for  sperm  candles.    Each  frame  contains  a  row  of  eighteen 


Fig.  143. 


moulds,  and  in  a  receptacle  at  the  bottom,  there  is  a  corre- 
sponding number  of  rolls  of  wicks  (the  plaited  or  braided 
wicks  before  mentioned)  connected  with  the  moulds.  In 
threading  the  moulds,  the  wick  is  left  to  protrude  at  the 


624 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


top ;  and  when  the  sperm  has  been  poured  in  and  the  candles 
have  set  or  cooled,  the  frame  is  drawn  forward  by  means  of 
a  lever,  directly  in  front  of  a  series  of  horizontal  rammers, 
which  are  made  to  press  against  the  conical  tips  of  the 
moulds.  The  candles,  in  passing  from  the  moulds,  draw 
after  them  sufficient  wick  to  re-thread  the  mould  for  the 
next  casting. 

The  candles  are  drawn  as  shown  at  a;  and  in  that  position 
they  are  firmly  held  by  a  hinged  board,  suitably  indented 
and  covered  with  flannel ;  while  a  circular  knife  moving  be- 
tween a  and  b  cuts  the  wicks  and  frees  the  candles.  The 
ends  of  tlie  wicks  are  then  caught  by  clasps  arranged  on  a 
rod  and  tightened  by  drawing  back  the  plungers,  which  bring 
with  them  at  the  same  time  the  conical  tips  of  the  moulds. 
The  whole  frame  is  then  placed  on  a  pair  of  rails  at  the  side. 
The  frames  are  brought  under  a  reservoir  of  sperm,  placed 
above  the  rails,  the  contents  of  which  are  kept  in  a  state  of 
fusion  by  steam  pipes.  Being  filled,  they  are  pushed  to  the 
end  of  the  railway  to  cool.  When  the  candles  have  set,  the 
excess  of  sperm  and  the  clasps  are  removed  from  the  top  ;  and 
the  frames  are  removed  on  a  suitable  truck  to  a  parallel  rail- 
way opposite,  and  are  then  moved  up  to  the  rammers  and 
drawn  as  before  mentioned.  Care  must  be  taken  to  keep  the 
clasps  in  their  proper  positions,  so  as  to  maintain  the  wicks 
in  the  centre  of  the  candles. 

Composition  candles  in  which  spermaceti  or  paraffine  enters 
largely  are  used  for  decorations,  being  colored  and  painted 
in  ornamental  designs.  This  branch  of  the  art  will  be 
treated  of  in  a  subsequent  section. 

Wax  candles^  though  expensive,  are  much  used  in  many 
countries  in  the  homes  of  the  wealthy,  on  festive  occasions, 
and  in  the  churches  of  several  religious  denominations.  We 
have  outlined  the  process  for  refining  and  bleaching  the  wax 
for  this  purpose.  The  wax  bleached  by  the  action  of  light 
is  much  the  best  for  nearly  all  purposes,  while  that  bleached 
by  the  aid  of  chemicals,  though  equally  white,  loses  much  of 
its  toughness  and  adhesive  property.  Wax,  and  especially 
beeswax,  added  to  other  materials  for  candles  generally  im- 


MANUFACTURE  OF  CANDLES. 


525 


proves  their  quality  and  appearance.  It  has  been  customary 
to  add  a  certain  quantity  to  spermaceti  and  stearic  acid  can- 
dles to  obviate  the  liability  of  these  candles  to  crystallize 
when  moulded,  causing  a  brittleness  and  a  cloudy  appearance. 

Moulding  Wax  Cayidles. — It  would  be  a  somewhat  difficult 
process  to  mould  wax  candles  in  any  of  the  many  moulding 
machines  we  have  described  and  illustrated  in  this  work, 
though  it  is  possible  to  do  so  if  great  care  be  taken  in  regu- 
lating the  heat  of  the  wax,  the  moulds,  etc.  For  moulding 
wax  candles  glass  moulds  have  been  found  the  most  desirable 
and  to  make  them  less  liable  to  fracture ;  they  are  coated  ex- 
ternally with  gutta  percha,  and  when  the  candles  are  to  be 
drawn  the  moulds  are  dextrously  dipped  into  warm  water,  and 
the  candies  withdrawn  while  the  mould  has  been  expanded  by 
the  heat.  Wax  has  also  the  property  of  greatly  contracting 
while  cooling,  causing  the  candles  when  moulded  to  crack. 

Wax  candles  are  most  frequently  made  by  basting.  For 
this  purpose  the  wicks  (either  twisted  or  plaited)  are  covered 
at  the  ends  with  small  tin  tubes,  to  protect  them  from  the 
moulten  wax;  they  are  then  suspended  upon  a  hoop  hanging 
over  a  furnace  having  a  large  round  copper  kettle  e,  Fig.  144, 
containing  the  melted  wax ;  this  kettle  has  a  rim  d  so  bent  at 
the  front  as  to  catch  the  dripping  wax  and  return  it  to  the 
kettle.  The  workman  standing  by  this  vessel  and  having 
the  hoop  with  the  wick  in  the  proper  position,  pours  with  the 
ladle  I  a  portion  of  wax  on  each  wick  i!i  succession,  turning 
the  hoop  at  the  same  time,  also  giving  a  twist  to  the  candles 
to  insure  a  uniform  coating.  By  the  time  the  first  basted 
wick  has  returned  to  him  it  may  be  sufficiently  cool  and  hard 
to  receive  another  coating  of  wax,  and  so  on  until  sufficient 
has  adhered  to  form  the  required  size,  which  is  regulated  by 
a  balance  or  by  the  practised  eye  of  the  operator. 

When  the  candles  have  acquired  the  requisite  size,  they 
are  finished  to  their  proper  length,  and  polished  by  rolling  on 
a  marble  slab  or  hard-wood  table  with  a  suitable  roller  like 
Fig.  145,  the  slab  or  table  being  dampened  with  water  to  pre- 
vent adhesion  :  the  tops  are  formed  with  a  suitable  tool  and 
the  lower  ends  cut  oft'  smoothly. 


526  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


For  the  laroje  bougies  or  cierges  used  in  the  ceremonies  of  the 
churches,  many  of  which  weigh  twenty  to  forty  pounds, 


Fig.  144. 


there  are  several  processes  of  making  besides  the  one  just 
described.    The  large  size  altar  candles  are  usually  made  by 

Fig.  145. 

first  soaking  the  wick  (which  is  part  cotton  and  part  linen) 
in  the  melted  wax,  then  forming  the  wax,  kept  soft  by  warm 
water,  into  long  strips  or  ribbons  and  covering  the  wicks, 
continuing  until  they  acquire  the  proper  thickness,  rolling 
and  polishing  as  described.  Or,  again,  the  candles  are  made 
of  the  requisite  size,  and  the  wicks  inserted  into  a  channel 


MANUFACTURE  OF  CANDLES. 


527 


bored  throuo;h  the  centre,  filling  up  the  channel  with  melted 
wax. 

There  have  been  made  several  machines  for  moulding  wax 
candles  in  a  continuous  length,  usually  in  the  shape  of  a 
press,  heated  by  steam  to  the  proper  temperature  necessary  to 
keep  the  wax  soft.  The  wick  is  inserted  in  such  a  manner 
that  it  is  concentrically  surrounded  with  wax  when  ejected 
from  the  spout  of  the  cylinder  of  the  press,  thus  forming  a 
continuous  candle  which  is  cut  into  the  required  length  and 
finished  as  described. 

Wax  has  so  many  uses  that  it  is  kept  at  a  price  too  high 
for  use  in  ordinary  candles ;  it  is  therefore  not  much  used  for 
candles  in  this  country.  But  it  is  a  material  that  might 
enter  into  many  of  the  better  class  of  composite  candles, 
which  see. 


528  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


SECTION  YII. 

THE  MANUFACTURE  OF  CANDLES  (Continued). 

Polishing  and  Finishing. 

Fou  the  common  candles  of  tallow  there  is  not  much 
attention  given  to  the  finish  or  the  bleaching.    They  are  cut 


Fi>c.  146. 


1 


at  the  ends  with  a  large  knife  attached  to  an  open  tray, 
having  a  gauge  board  to  regulate  the  length,  and  are  sub- 


Fig.  147. 


mitted  to  the  action  of  air  and  light,  by  being  placed  in  a 
wire  grating  of  lead  upon  a  proper  table  or  framework,  as 


MANUFACTURE  OF  CANDLES. 


529 


shown  by  Figs.  146  and  147.  This  frame  and  wire  are 
applied  for  bleaching  stearic  acid  and  other  fine  candles. 

The  better  class  of  candles  are  polished  by  hand  by  being 
rubbed  with  a  soft  woollen  cloth  moistened  with  ammoniated 
alcohol,  or  are  polished  by  a  machine  made  for  the  purpose. 
Fig.  148  is  a  drawing  of  a  simple  machine  in  general  use  in 


Fig.  148. 


France ;  A,  being  the  hopper  in  which  the  candles  are 
arranged,  and  from  which  they  are  taken  singly  by  the 
fluted  cylinder  B.  This  latter,  in  revolving  gives  them  to 
the  circular  saw  which  cuts  the  ends,  when  they  drop  upon 
the  erwiless  belt  of  woollen  cloth,  running  on  the  rollers  G  G  G 
and  passing  around  the  drums  H  H.  Three  other  rollers  D  D  D 
covered  with  cloth,  run  by  aid  of  pinions  E  EE,  are  run  in  an 
opposite  direction.  By  these  alternate  motions  the  candles 
are  made  smooth  and  glossy,  and  delivered  into  the  recep- 
tacle I. 

A  more  complete  polishing  machine  is  shown  by  Figs.  149 
and  150 ;  A  A  being  the  framework  strengthened  by  the 
beam  B,  the  belt  C  driving  the  pulley  D  or  the  loose  one  E, 
the  moving  axle  carries  the  two  fly-wheels  HH,  moving  the 
shafts  1 1,  and  giving  motion  to  the  rubber  J  and  the  rubbing 
sheave  M.  The  belt  'N  connects  M  and  The  latter  sheave 
is  fixed  in  a  horizontal  shaft  0  with  a  pinion  wheel  P  at  the 
34 


530  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

end,  working  into  a  large  toothed  wheel  Q.  The  shaft  0 
also  carries  two  small  wheels  with  square  teeth  II,  which 


give  motion  to  an  endless  chain  2  composed  of  iron  rods, 
and  between  which  the  candles  3  are  placed.  A  small  table 
covered  with  woollen  cloth  is  fixed  under  the  endless  chain 
on  which  the  candles  roll  as  they  are  drawn  forward  from 
an  incline,  ranging  parallel  with  each  other.  The  candles 
are  retained  in  their  position  under  the  rubber,  by  means  of 


MANUFACTURE  OF  CANDLES. 


531 


lb 


the  guide  7  regulated  by  springs  8  8,  and  when  sufficiently 
rubbed  and  polished  are  deposited  on  the  table  at  the  other 
end  of  the  machine. 

Almost  all  stearic  acid,  paraffine,  and  spermaceti  candles 
and  many  of  the  composite  candles  are  now  made  so  per- 
fectly by  finely  finished  moulds,  that  they  require  but  little 
polishing  and  finishing;  yet,  some  machinery  for  this  pur- 
pose, however  simple  it  may  be,  is  indispensable  to  give  a 
smooth  and  glossy  appearance  to  the  finished  candles. 


532  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


SECTIO]^  VIII. 

THE  MANUFACTURE  OF  CANDLES  (Continued). 

Composite  and  Patent  Candles. 

From  the  nnmberof  materials  heretofore  mentioned,  there 
are  a  great  variety  of  candles  made  with  as  many  different 
names,  yet  they  have  much  sameness  in  their  characteristics 
as  their  composition  is  usually  of  two  or  more  ingredients, 
thus  w^e  see  stearo-palmitic,  margaro-elaidic,  stearo-cocinic, 
etc.  etc.,  but  with  fancy  names.  The  value  of  these  candles 
depends  upon  their  clean  burning  and  light-giving  properties 
as  much  as  their  handsome  appearance,  which  in  all  cases 
should  be  as  white  and  transparent  as  possible.  Sometimes 
candles  are.  made  having  a  part  neutral  fat  with  the  stearic, 
palmitic,  or  cocinic  acids,  but  as  a  rule  they  have  not  the 
illuminating  power  of  the  fatty  acids  ;  then  again  their  melt- 
ing point  is  generally  too  low. 

Belmmit  spe?'m  candles  are  made  from  a  mixed  body  of 
stearic  and  cocinic  acids  combined  with  a  portion  of  paraffine. 

Belmont  wax  candles  are  we  believe  stearic  acid  and  a  por- 
tion of  wax  tinted  a  creamy  white  with  gamboge. 

Star  candles  have  usually  a  base  of  stearic  acid  prepared 
from  tallow  and  lard. 

Cerophane  bougies,  a  French  invention,  are  we  think  a 
composition  of  very  white  stearic  acid,  with  ten  to  twelve 
per  cent,  of  bleached  beeswax,  made  transparent  by  careful 
moulding. 

Adamantine  candles,  named  thus  from  their  hardness,  are 
made  from  a  stearic  acid  produced  from  tallow  which  has  the 
highest  melting  point,  about  68.3°  C.  (155°  F.).  Though 
not  so  white  or  transparent,  they  give  a  good  white  light. 

Artificial  wax  candles  are  made  in  varying  proportions  of 


MANUFACTURE  OF  CANDLES. 


533 


stearic  acid  and  wax,  principally  beeswax,  though  there  are 
several  vegetables  waxes  used  which  have  to  be  previously 
bleached.  Wax  candles  have  a  creamy  white  color  which  is 
usually  imparted  to  the  artificial  wax  by  means  of  yellow  pig- 
ment. There  is  also  a  certain  art  in  the  moulding  of  these 
candles  necessary  to  give  a  waxy  appearance  and  to  deserve 
their  name.  This  consists  principally  in  so  melting  the  mate- 
rial and  keeping  it  quiet  for  about  half  an  hour,  while  the 
temperature  has  reached  the  proper  point,  when  it  is  carefully 
run  into  the  previously  warmed  moulds  which  are  gradually 
cooled. 

Diaphanous  candles  are  also  a  French  invention,  and  are 
we  believe  made  of  a  superior  stearic  acid,  from  lard  and 
some  of  the  vegetable  waxes  (say  Japan  wax),  which  latter 
has  been  purified  by  chemicals.  Care  also  is  necessary  in 
moulding  to  give  a  great  transparency  by  a  due  regulation 
of  the  heat  both  of  the  moulds  and  the  fatty  bodies. 

Composition  candles. — By  this  name  so  many  different  can- 
dles have  been  made  that  it  would  be  almost  impossible  to 
give  formulas.  The  term  is  applied  to  candles  that  have  in 
their  composition  certain  neutral  fats  or  sebacic  acids  in 
certain  proportions,  one  giving  to  the  other  a  quality  to 
improve  either  their  consistency  or  lighting  power. 

From  these  formulas  the  intelligent  manufacturer  should 
receive  such  hints  as  by  experiment  would  enable  him  to 
make  any  candle  he  might  desire. 

Various  fatent  candles. — From  the  many  candles  that  have 
at  times  been  patented,  and  which  have  been  more  ingenious 
than  useful,  we  must  select  a  few,  for  they  may  serve  as  hints 
to  other  inventions.  In  England  candles  have  been  moulded 
with  a  perforation  through  the  centre  (Fig.  153),  the  diameter 
regulated  to  the  size  of  the  candle;  the  wick  is  drawn  through 
or  a  small  wick  having  a  weight  attached  (Fig.  154).  which 
carries  down  the  wick  as  the  candle  is  consumed,  and  re- 
quires no  snufiiing.  Figs.  151  and  152  showcandles  moulded  in 
solid  form,  the  wicks  being  but  two  or  three  inches  long,  and 
attached  to  a  tube  (Fig.  158)  of  a  shape  to  fit  the  candle,  and 
which  descends  as  the  fat  is  melted  and  consumed.    Fig.  155 


534  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 

is  a  candle  moulded  in  oval  form  in  which  is  to  be  placed  a 
flat  wick  for  the  purpose  of  giving  a  larger  flame  and  in- 


Fig.  151.    Fig.  152.  Fig.  153.  Fig.  154.    Fig.  155. 


I 
i 


created  light.  Figs.  156  and  157  are  devices  for  making 
candles  in  two  parts,  a  hollow  exterior  cylinder  6,  and  an 
interior  one  a,  the  latter  being  one-eighth  of  an  inch  less  in 
diameter  than  the  hole  in  6  ;  this  space  between  the  two  being 

Fig.  156.  Fig.  157.        Fig.  158. 


filled  with  the  wick,  and  if  the  interior  cylinder  has  a  per- 
foration as  seen  in  Fig.  157  the  wick  will  be  supplied  with 
air  similar  to  an  argand  lamp. 

Similar  devices  for  supplying  air  to  the  flame  of  the  can- 
dle have  been  patented,  and  also  to  prevent  the  candle  gut- 


MANUFACTURE  OF  CANDLES. 


535 


tering  when  carried,  the  melted  fats  running  into  perforations 
beside  the  wick.  For  these  candles  it  is  usual  to  mould  them 
in  solid  form  and  perforate  them  through  their  length  with 
a  suitably  shaped  tool.  Fig.  159  shows  one  that  makes  a 
triangular  perforation,  through  the  centre  of  which  a  coated 
wick  is  drawn,  leaving  three  channels  for  the  access  of  air  or 
for  permitting  the  overflow  of  fat  to  run  into  w^hen  melted 
faster  than  it  can  be  consumed,  or  dropping  when  the  candle  is 
carried  about. 


Fig.  159.  Fig.  160. 


Many  improvements  in  the  moulds  for  candles  might  be 
mentioned.  Fig.  160  represents  one  that  possesses  much  merit ; 
a  a  is  the  shaft  of  the  mould,  6  the  box  or  trough.  The 
lower  portion  of  the  mould  is  compressed  at  cc,  to  form  a 
resting  place  for  the  tip  which  tip  is  widened  at  the  outer 
end  that  it  may  be  forced  up  to  loosen  the  candle  before  being 


536  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


drawn  when  it  again  falls  into  its  place.  These  moulds  are 
made  of  a  hard  material  and  of  less  weight  and  thinner  sides 
that  they  may  be  the  sooner  cooled  or  heated  ;  moreover,  they 
are  susceptible  of  a  finer  polish  to  their  interior  surface, 
thereby  moulding  a  better  finished  candle. 

To  prevent  the  guttering  of  candles  metallic  cups  have  been 
devised  as  seen  in  Figs.  161  and  162,  a  simple  cup  of  thin 
metal  to  be  placed  upon  the  top  of  a  candle ;  the  wick  coming 
through  the  hole  is  lighted,  and,  as  the  material  is  melted  and 
consumed,  the  cup  descends,  preventing  any  overflow.  The 
inventor  proposes  to  place  on  top  of  this  cup  another  holding 
a  circular  tube  of  glass  or  mica  to  act  as  a  chimney,  as  shown 
in  the  cut.  Fig.  163. 

Another  ingenious  invention  of  a  candle  or  bougie  to  burn 
on  water  is  represented  by  Fig.  164,  very  useful  for  a  night 
light.  They  are  made  of  stearic  acid  or  wax.  A  plate  of 
metal  A  covering  the  vessel  of  water  has  attached  a  tube  in 
which  the  candle  floats,  and  which  acts  as  a  guide  for  it  while 
it  is  consuming  and  burns  at  the  surface.  There  can  also  be 
placed  upon  the  tube  graduated  marks  showing  the  time  of 
night  by  the  length  of  candle  consumed  (Fig.  165). 


Fig.  161.  Fig.  163.  Fig.  164.       '  Fig,  165. 


Fig.  162. 


It  would  be  impossible  in  our  limited  space  to  give  all -the 
ingenious  devices  and  patents  that  pertain  to  these  useful 
articles.  What  we  have  given  may  serve  to  stimulate  the  in- 
ventive powers  of  our  readers  who  may  make  something 
much  better. 


MANUFACTURE  OF  CANDLES. 


537 


SECTION"  IX. 

THE  MANUFACTURE  OF  CANDLES  (Concluded). 

Decorated  and  Colored  Candles,  Tapers,  I^'ight  Lights,  Etc. 

With  the  advanced  taste  for  house  decorations,  illumi- 
nated, decorated,  and  colored  candles  find  a  conspicuous 
place,  and  there  has  been  a  rapid  advancement  towards  per- 
fection in  them,  for  they  are  seen  in  very  handsome  colors, 
with  decorations  that  may  be  considered  quite  artistic,  these 
being  upon  tints  that  form  a  suitable  ground  for  their  proper 
display. 

Colored  Candles. — The  usual  base  for  these  candles  is  stearic 
acid  or  spermaceti,  though  they  are  found  of  wax  and  of 
paraffine,  but  as  parafiine  will  not  hold  color,  there  Las  to  be 
some  other  substance  combined  with  it  that  can  be  colored. 
Thus  we  find  nearly  all  the  colored  candles  are  a  combination 
of  several  ingredients,  but  generally  of  fine  materials,  as  the 
base  should  be  as  white  and  transparent  as  possible.  Colored 
candles  are  sometimes  made  that  are  colored  only  on  tbe 
outer  surface.  This  is  done  by  moulding  them  in  very  thin 
moulds,  so  that  w4ien  the  colored  material  is  placed  in  them, 
it  cools  rapidly,  when  they  are  emptied  of  the  internal  liquid 
part,  while  the  solidified  part  has  adhered  to  the  inner  sur- 
face of  the  moulds.  They  are  then  filled  with  the  material 
for  the  body  of  the  candle,  taking  care  to  have  it  of  as  low  a 
temperature  as  possible,  so  that  it  wnll  not  melt  the  colored 
surface.  When  cold  they  are  drawn  as  usual,  and  if  they  ad- 
here too  strongly,  the  moulds  are  dextrously  dipped  in  warm 
water,  which  expands  them  so  that  the  candle  is  loosened. 
This  process  is  seldom  followed,  as  it  entails  too  much  labor 
for  a  large  business,  and  is  not  rapid  enough. 

The  colors  for  candles  have  heretofore  been  of  ^mineral 


538  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


oriojin  with  but  few  exceptions,  for  there  are  few  vegetable 
colors  which  will  color  fat  that  are  permanent.  And  there  are 
well-grounded  objections  to  the  use  of  many  of  the  mineral 
colors  in  vogue,  that,  when  combined  with  the  fatty  body 
and  burnt,  give  off  the  oxides  of  the  minerals  to  contaminate 
the  air  of  the  apartments  with  poisonous  vapors.  Thus 
arsenic,  lead,  copper,  mercury,  and  zinc,  the  base  of  most  of 
these  colors,  are  volatilized  and  become  deleterious  to  health, 
so  that  such  colors  must  be  avoided  if  possible.  The  vegeta- 
ble colors  of  alkanet  for  red,  and  gamboge  or  roucou  for  yel- 
low, are  quite  fugitive  and  soon  fade  on  exposure  to  light,  so 
that  the  use  of  minerals  is  to  some  extent  necessary. 

Aniline  colors  have  also  had  the  same  objections,  and 
have  not  been  permanent,  but  although  they  have  in  many 
instances  a  base  of  metallic  oxide,  yet  at  this  time  they  are 
made  so  durable  that  they  must  serve  to  give  nearly  all  the 
colors  needed,  and  whatever  metallic  substances  they  may 
contain  are  in  such  minute  quantity  when  burnt  as  to  be 
almost  imperceptible. 

For  yellow  there  are  used  gamboge,  roucou,  chromate  of 
lead,  and  naphthaline  yellow. 

For  red,  alkanet  root,  minium,  vermilion,  and  several 
permanent  aniline  reds. 

For  blue,  ultramarine,  sulphate  of  copper,  and  aniline 
blue. 

For  green,  distilled  verdigris,  Schweinfurt  green,  or  a 
mixture  of  yellow  with  blue. 

For  purple  or  violet,  a  mixture  of  blue  with  red:  and 
for  the  neutral  tints,  some  of  the  brown  oxides  of  iron,  yel- 
low ochres,  and  Frankfort  black.  With  the  articles  here 
mentioned,  nearly  any  shade  can  be  obtained. 

It  has  been  quite  customary  for  manufacturers  to  use  a 
little  ultramarine  to  give  a  bluish-white  shade  to  the  white 
candles,  or  to  disguise  the  yellowish  shade  of  their  fats. 

Toy  candles  are  the  colored  candles  above  mentioned,  made 
of  small  size,  and  usually  of  a  mixture  of  stearic  acid  and 
paraffine.    They  are  made  20,  40,  60,  and  80  to  the  pound. 

Decorated  candles  have  become  much  in  vogue,  as  are  the 


MANUFACTURE  OP  CANDLES. 


539 


better  class  of  candles  generally,  for  lighting  the  drawing- 
rooms  of  society,  and  in  fact  are  becoming  more  in  use  from 
the  objection  to  gas  as  made  in  our  larger  cities  being  usu- 
ally quite  impure,  and  when  burning,  throwing  otf  sulphur- 
etted hydrogen  to  the  injury  of  the  colors  of  fine  fabrics 
used,  as  well  as  of  valuable  paintings.  Thus  we  see  the  old- 
fashioned  candelabra  again  in  use,  and  candles  more  in  vogue. 

From  this  circumstance  we  have  given  this  subject  some 
attention,  for  there  is  no  good  reason  why,  with  our  culti- 
vated taste,  we  should  be  dependent  upon  France  and  Eng- 
land for  these  useful  articles. 

The  base  of  almost  all  the  decorated  candles  we  have  seen 
is  a  compound  of  stearic  acid  and  wax  or  parafiine,  and  many 
that  are  called  wax  have  really  but  little  wax  in  their  com- 
position, nor  can  it  be  considered  much  to  their  disadvantage 
for  these  composite  candles,  while  costing  one-half  the  price 
of  pure  wax,  have  nearly  as  good  an  appearance,  and  give  as 
white  and  good  a  light.  With  the  materials  named,  and  in 
the  proportions  given  in  our  last  chapter,  with  suitable 
colors  as  we  have  just  named,  with  care  in  the  manipulations 
when  moulding,  there  cannot  be  much  difficulty  in  making 
very  satisfactory  candles.  For  this  purpose,  above  all,  care 
must  be  taken  that  the  material  has  a  high  melting-point  to 
insure  their  retaining  their  form  in  the  warmest  weather, 
and  that  they  may  not  bend  when  placed  in  the  candelabra. 

We  here  illustrate  a  few  styles  of  decoration,  but  they  are 
given  merely  as  hints,  for  the  colors  and  designs  are  innume- 
rable. Fig.  166  will  serve  to  show  how  effective  they  can  be 
made  for  the  purpose  of  decoration. 

As  a  ground  for  these  decorations,  whether  done  by  hand 
or  transferred  by  the  process  of  decalcomanie,  a  suitable  var- 
nish is  put  on  the  candle.  This  varnish  is  made  by  dissolv- 
ing gum  damar  in  rectified  oil  of  turpentine  or  absolute  alco- 
hol, and  should  be  quite  thick  that  it  will  not  require  renew- 
ing, or  that  one  coating  may  be  sufficient.  These  designs  for 
decalcomanie  are  found  in  commerce  for  the  purpose  of  the 
decoration  of  various  articles,  and  are  in  nearly  every  con- 
ceivable design,  and  many  are  made  for  this  purpose  especially, 


TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


and  it  is  usual  for  the  dealers  in  them  to  give  instruction  for 
their  proper  application.  They  are  printed  upon  a  porous 
paper  :  and  when  the  design  is  pressed  upon  the  warmed  var- 
nished surface,  and  has  hardened,  the  paper  is  wet  with  water 


Fig.  166. 


and  afterwards  gently  rubbed  off,  leaving  the  design  adhering 
to  the  candle.  When  the  candles  are  decorated  by  hand,  it  is 
customary  to  have  them  of  the  best  quality,  and  they  are 
prepared  with  a  coating  of  the  damar  varnish  spoken  of,  or 
a  still  better  varnish  is  now  made  with  gum  mastic.  It  is 
not  our  province  to  give  further  details  for  this  art,  as  it 
pertains  to  another. 

Wax  Tapers. — These  useful  articles  have  much  importance 
as  they  are  employed  for  many  purposes:  for  lighting  the 
gas,  for  melting  the  wax  for  sealing  letters  (the  twisted 
taper),  for  night  lights,  etc.  The  twisted  tapers  are  in  a 
great  variety  of  forms  and  sizes,  and  usually  in  bright  colors  ; 
a  hollow  coil  is  the  commonest  form.  They  are  made  of  wax 
as  a  base  with  a  small  percentage  of  either  stearic  acid,  pa- 
raffine,  or  fine  resin.  We  illustrate  a  machine  used  for  this 
purpose  (Figs.  167-170),  where  it  will  be  seen  that  the  wick, 


MANUFACTURE  OF  CANDLES. 


541 


usually  several  fine  yarns  of  cotton  twisted  to  suit  the  thick- 
ness of  the  taper  (generally  about  a  quarter  of  an  inch  thick, 
often  thinner),  is  wound  from  one  wooden  drum  to  the  other. 


the  wnck  passing  through  an  oval  copper  pan,  D,  having  a 
raised  rim,  G  G'.  This  pan  contains  the  melted  wax  kept 
fluid  by  the  brazier  E,  and  passing  through  the  hook  H, 


542  TECHNICAL  TREATISE  ON  SOAP  AND  CANDLES. 


placed  in  the  bottom  of  the  pan.  F  is  a  metallic  bevelled 
ring  through  which  the  dipped  wick  passes,  and  which  serves 
to  regulate  the  size  of  the  taper.  It  can  be  made  in  any 
form  to  give  other  shaped  tapers.  In  working  this  machine, 
it  is  only  necessary  to  have  the  drums  and  copper  in  the 
position  shown,  and  wind  the  taper  from  A  to  B,  having  B 
at  such  a  distance  that  the  wax  may  cool  before  reaching  it. 
As  the  wick  requires  more  than  one  dipping,  the  taper  is 
next  wound  from  B  to  A,  changing  the  gauge  F  to  the  other 
end  of  the  copper.  Figs.  168-170  show  the  detached  parts. 
If  the  tapers  are  to  be  gas-lighters,  they  are  cut  into  lengths 
of  about  twenty  inches ;  if  the  twisted  tapers,  they  are  cut 
into  suitable  lengths,  slightly  warmed,  and  wound  on  suit- 
able forms  to  give  them  the  desired  shape. 

Night  Lights  or  Tapers. — The  most  common  form  for  these 
is  a  cylinder  of  wax,  stearic  acid,  or  a  combination  of  other 
solid  sebacic  acids,  in  size  about  one  and  a  quarter  inches  in 
diameter,  by  one  and  a  half  in  length.  They  are  moulded 
in  tin  tubes,  generally  six  dozen  in  one  frame,  and  made 
solid,  the  wick  being  placed  in  afterwards.  This  wick  is 
usually  quite  small,  that  the  taper  may  be  consumed  very 
slowly. 


APPENDIX. 


THF^  METKIC  SYSTEM  OF  WEIGHTS  AND  MEASURES. 

The  United  States  being  the  first  to  introduce  the  decimal 
system  into  the  coinage  of  the  country,  and  to  demonstrate  its 
superior  utility,  it  is  remarkable  that  we  have  hesitated  so  long 
in  regard  to  the  substitution  of  the  same  simple  and  rational 
system  of  weights  and  measures  for  the  complicated  and  con- 
fused standards  in  general  use. 

In  May,  1866,  the  Committee  on  Coinage,  Weights,  and  Mea- 
sures presented  to  the  House  of  Representatives  an  exhaustive 
report,  accompanied  by  bills  authorizing  the  introduction  of 
the  metric  system  into  the  various  departments  of  trade,  and 
making  all  contracts,  based  on  this  system  of  weights  and 
measures,  valid  before  any  court  in  the  United  States.  They 
said : — 

''THE  METRIC  SYSTEM. 

''It  is  orderly,  simple,  and  perfectly  harmonious,  having  use- 
ful relations  between  all  its  parts.  It  is  based  on  the  meter, 
which  is  the  principal  and  only  arbitrary  unit.  The  meter  is  a 
measure  of  length,  and  was  intended  to  be,  and  is,  very  nearly 
one  ten-millionth  of  the  distance  on  the  earth's  surface  from 
the  equator  to  the  pole.    It  is  89.37  inches,  very  nearly. 

'  The  are  is  a  surface  equal  to  a  square  whose  side  is  10 
meters.    It  is  nearly  four  square  rods. 

*'  The  liter  is  the  unit  for  measuring  capacity,  and  is  equal  to 
the  contents  of  a  cube  whose  edge  is  a  tenth  part  of  the  meter. 
It  is  a  little  more  than  a  wine  quart. 

"  The  gramme  is  the  unit  of  weight,  and  is  the  weight  of  a 
cube  of  water,  each  edge  of  the  cube  being  one  one-hundredth 
of  the  meter.    It  is  equal  to  15.432  grains. 

"  The  stere  is  the  cubic  meter. 

"Each  of  these  units  is  divided  decimally,  and  larger  units 
are  formed  by  multiples  of  10,  100,  &;c.  The  successive  mul- 
tiples are  designated  by  the  prefixes,  deka^  hecto,  kilo,  and  myria  ; 
the  subordinate  parts  by  deci,  centi,  and  milli,  each  having  its 
own  numerical  significance. 

"The  nomenclature,  simple  as  it  is  in  theory,  and  designed 

1 


544 


THE  METRIC  SYSTEM. 


from  its  origin  to  be  universal,  can  only  become  familiar  by 
use.  Like  all  strange  words,  these  will  become  familiar  hy 
custom,  and  obtain  popular  abbreviations.  A  system  which 
has  incorporated  with  itself  so  many  different  series  of  weights, 
and  such  a  nomenclature  as  'scruples,'  'pennyweights,'  'avoir- 
dupois,' and  with  no  invariable  component  word,  can  hardly 
protest  against  a  nomenclature  whose  leading  characteristic  is  a 
short  component  word  with  a  prefix  signifying  number.  We 
are  all  familiar  with  thermometer ,  haroraeter^  diameter^  gasometer^ 
&c.,  with  telegram^  monogram^  &c.,  words  formed  in  the  same 
manner. 

"  After  considering  every  argument  for  a  change  of  nomen- 
clature, your  committee  have  come  to  the  conclusion  that  any 
attempt  to  conform  it  to  that  in  present  use  would  lead  to  con- 
fusion of  weights  and  measures,  would  violate  the  early  learned 
order  and  simplicity  of  metric  denomination,  and  would  seri- 
ously interfere  with  that  universality  of  system  so  essential  to 
international  and  commercial  convenience. 

"When  it  is  remembered  that  of  the  value  of  our  exports 
and  imports,in  theyear  ending  June  30, 1860,  in  all  $762,000,000, 
the  amount  of  near  $700,000,000  was  with  nations  and  their  de- 
pendencies that  have  now  authorized,  or  taken  the  preliminary 
steps  to  authorize,  the  metric  system,  even  denominational  uni- 
formity for  the  use  of  accountants  in  such  vast  transactions 
assumes  an  important  significance.  In  words  of  such  universal 
employment,  each  word  should  represent  the  identical  thing  in- 
tended, and  no  other,  and  the  law  of  association  familiarizes  it. 

"Your  committee  unanimously  recommend  the  passage  of 

the  bills  apd  joint  resolutions  appended  to  this  report  

The  metric  system  is  already  used  in  some  arts  and  trades  in 
this  country,  and  is  especially  adapted  to  the  wants  of  others. 
Some  of  its  measures  are  already  manufactured  at  Bangor,  in 
Maine,  to  meet  an  existing  demand  at  home  and  abroad.  The 
manufacturers  of  .the  well-known  Fairbanks'  scales  state:  'For 
many  years  we  have  had  a  large  export  demand  for  our  scales 
with  French  weights,  and  the  demand  and  sale  are  constantly 
increasing.'  Its  minute  and  exact  divisions  specially  adapt  it 
to  the  use  of  chemists,  apothecaries,  the  finer  operations  of  the 
artisan  and  to  all  scientific  objects.  It  has  always  been  and  is 
now  used  in  the  United  States  coast  survey.  Yet  in  some  of 
the  States,  owing  to  the  phraseology  of  their  laws,  it  would  be 
a  direct  violation  of  them  to  use  it  in  the  business  transactions  of 
the  community.  It  is,  therefore,  very  important  to  legalize  its  use, 
and  to  give  to  the  people,  or  that  portion  of  them  desiring  it,  the 
opportunity  for  its  legal  employment,  while  the  knowledge  of 
its  characteristics  will  be  thus  diffused  among  men." 


WEIGHTS  AND  MEASURES.  545 

WEIGHTS  AND  MEASURES. 
APOTHECARIES'  WEIGHT,  U.  S. 

Pound.  Ounces.  Drachms.  Scruples.  Grains. 

ft  1       ==       12      =      96       =      288  =  5760 

§   1       =        8       =        24  =  480 

3  1=         3  =  60 

B  1  =  gr.  20 

The  imperial  standard  Troy  weight,  at  present  recognized  by  the  British 
laws,  corresponds  with  the  apothecaries'  weight  in  pounds,  ounces,  and 
grains,  but  differs  from  it  in  the  division  of  the  ounce,  which,  according  to 
the  former  scale,  contains  twenty  pennyweights,  each  weighing  twenty- 
four  grains. 

AVOIRDUPOIS  WEIGHT. 

Pound.  Ounces.  Drachms.  Troy  grains. 

lb  1       =       16       x=       256       =  7000. 

oz.   1       =        16      =  487.5 

dr.   1       =  27.34375 

Relative  Value  of  Troy  and  Avoirdupois  Weights. 

Pound.  Pounds.  Pound.     Oz.  Grains. 

1  Troy  =   0.822857  Avoirdupois  =   0      13  72.5 

1  Avoirdupois  =    1.215277  Troy  —   1        2  280. 

WINE  MEASURE,  U.  S. 

Gallon.      Pints.   Fluidounces.    Fluidrachms.     Minims.    Cubic  inches. 

Cong.  1    =    8    =    128     =     1024  =*  61440  =  231. 

O  1    =     16     =       128  =  7680  =  28.875 

f|   1     =         8  =  480  =  1.8047 

f5  1  =  TTj^  60  =  0.2256 

IMPERIAL  MEASURE. 

Ado^pted  by  all  the  British  College. 

Gallon.         Pints.       Fluidounces.     Fluidrachms.  Minims. 

1     =     8     =     160      =     1280  =  76800 

1     =      20      =      160  =  9600 

1       =         8  =  480 

1  =  60 

Relative  Value  of  Apothecaries^  and  Imperial  Measures. 

apothecaries'  MEASUEE.  IMPERIAL  MEASURE. 


1  pint 

1  fluidounce 
1  fluid  rachm 
1  minim 

IMPERIAL  MEASURE.  APOTHECARIES'  MEASURE. 

Gallon.    Pints.    Fluidoz.    Fluidrms.  Minims 

1  gallon        =  119  5  8 

1  pint  =  1         3  1  38 

1  fluidounce  =  7  41 

1  fluidrachm  =  58 
1  minim        =  0.96 


Pints. 

Fluidozs. 

Fluidrms. 

Minims. 

6 

13 

2 

23 

16 

5 

18 

1 

0 

20 

1 

2.5 

1.04 

35 


3 


546 


WEIGHTS  AND  MEASURES. 


Belative  Value  of  Weights  and  Measures  in  Distilled  Water  at  60^  Fahr. 
1.  Value  of  Apothecaries'  Weight  in  Apothecaries'  Measure. 

Pints.     Fluidoz.    Fluidr.  Minims. 

1  pound  =  0.7900031  pints           =  0  12  5  7.2238 

1  ounce  =  1.0533376  fluidounces  =  0  1  0  25.6020 

1  drachm  ==  1.0533376  fluidrachms  =  0  0  1  3.2002 

1  scruple  =  0  0  0  21.0667 

1  grain  =  0  0  0  1.0533 


3.  Value  of  Apothecaries' 


1  gallon  =  10.12654270  pounds 
1  pint  =   1.26581783  pounds 

I  fluidounce  =.   0.94936332  ounces 
1  fluidrachm  =    0.94936332  drms. 
1  minim        =   0.94936332  grains 


asure  in  Apothecaries'  Weight. 

Pounds.  Oz.  Dr.  Sc.     Gr.  Grains. 

=  10  1  4  0  8.88  =  58328.886 

=    1  3  1  1  11.11  =  7291.1107 

=    0  0  7  1  15.69  =  455.6944 

=    0  0  0  3  16.96  =  56.9618 

=  1.9493 


3.  Value  of  Avoirdupois  Weight  in  Apothecaries'  Measure. 

Pints.  Fluidozs.  Fluidrms.  Minims. 

1  pound        =   0.9600732  pints  =   0        15        2  53.3622 

1  ounce        =   0.9600732  fluidounces  =    0         0        7  40.8351 


4.  Value  of  Apothecaries'  Measure  in  Avoirdupois  Weight. 

1  gallon  =  8.33269800  pounds. 
1  pint  =   1.04158725  pounds. 

1  fluidounce  =   1.04158725  ounces. 


5.  Value  of  Imperial  Measure  in  Apothecaries'  and  Avoirdupois  Weights. 

Imperial  Measure.    Apothecaries' Weight.    Avoirdupois  Weight.  Grains.    Cubic  inches. 

1  gallon  =12R)li  63  2B0gr.  =  10Ib05  =70,000  =277.27384 

1  pint  =    1     6    1     2    10      =  1     4   =  8,750     =  34.65923 

1  fluidounce  =  7     0    17.5   =         1    =    437.5  =  1.73296 

1  fluidrachm  =  2    14.69  =  54.69=  0.21662 

1  minim  =  0.91=  0.00361 

In  converting  the  weights  of  liquids  heavier  or  lighter  than  water  into 
measures,  or  conversely,  a  correction  must  be  made  for  specific  gravity.  In 
converting  weights  into  measures,  the  calculator  may  proceed  as  if  the  liquid 
was  water,  and  the  obtained  measure  will  be  the  true  measure  inversely  as 
the  specific  gravity.  In  the  converse  operation,  of  turning  measures  into 
weights,  the  same  assumption  may  be  made,  and  the  obtained  weight  will 
be  the  true  weight  directly  as  the  specific  gravity. 

4 


TABLES 

SHOWING  THE 

RELATIVE  VALUES  OF  FRENCH  AND  ENGLISH  WEIGHTS 
AND  MEASURES,  &c. 


Measures  of  Length. 


Millimetre 
Centimetre 
Decimetre 
Metre 


Decametre 

Hectometre 

Kilometre 

Mjriametre 
« 

Inch  Cj\  yard) 
Foot  (i  yard) 
Yard 

Fathom  (2  yards) 
Pole  or  perch  (5^  yards) 
Furlong  (220  yards) 
Mile  (1760  yards) 
Nautical  mile 


0.03937 
0.393708 
3.937079 
39.37079 
3.2808992 
1.093633 
32.808992 
328.08992 
3280.8992 
1093.633 
10936.33 
6.2138 
2.539954 
3.0479449 
0.91438348 
1.82876696 
5.029109 
201.16437 
1609.3149 
1852 


inch. 
(( 

inches. 
it 

feet. 

yard. 

feet. 
<( 

(( 

yards, 
miles. 

centimetres, 
decimetres, 
metre. 

metres. 


5 


648 


VALUES  OF  FRENCH  AND  ENGLISH 


Superficial  Measures. 


Square  millimetre 

square  inch. 

= 

0.00155 

u 

"  centimetre 

0.155006 

li 

(( 

decimetre 

15.50059 

u 

inches. 

(I  a 

0.107643 

foot. 

"     metre  or  centiare 

1550.05989 

inches. 

10.764299 

<( 

feet. 

u            n  « 

1.19f^033 

yard 

Are 

1076.4299 

feet. 

119.6033 

ii 

yards. 

n 

0.098845  rood. 

Hectare 

11960.3326 

square  yards. 

2.471143 

acres. 

Square  inch 
(( 

*'  foot 

"  yard 

"      rod  or  perch 
Rood  (1210  sq.  yards) 
Acre  (4840  sq.  yards) 


=     645.109201  square  millimetres. 


6.451367 

9.289968 

0.836097 
25.291939 
10.116775  ares. 

0.404671  hectare. 


centimetres 
decimetres, 
metre, 
metres. 


Measures  of  Capacity. 


10 
100 
1000 


Cubic  millimetre 

"  centimetre  or  millilitre  ; 
"     centimetres  or  centilitre  : 

"  *'  decilitre  =  6.102705 


0.000061027  cubic  inch. 
0.061027         "  " 
0.61027  "  " 


litre  = 


Decalitre 

u 

Hectolitre 

Cubic  metre  or  stere  or  kilolitre 
Myrialitre 


61.0270515 
1.760773 
0.2200967 
610.270515 
2.2009668 
3.531658 
22.009668 

1.30802 
35.3165807 
353.165807 


"  inches. 

U  ii 

imp'l  pint. 
"  gal'n. 
cubic  inches, 
imp.  gal'ns. 
cubic  feet, 
imp.  gal'ns. 
cubic  yard. 
"  feeto 


WEIGHTS  AND  MEASURES,  ETC. 


519 


Cubic  inch 
"  foot 
"  yard 


=  16.386176  cubic  centimetres. 
=^   28.315312  "  decimetres. 

=     0.764513422     "  metre. 


American  Measures. 

Winchester  or  U.S.  gallon  (231  cub. in.)      =      3.785209  litres. 

"    bushel(2150.42cub.in.)=     35.23719  " 
Chaldron  (57.25  cubic  feet)  =  1621.085  " 

British  Imperial  Measures. 

Gill  =  0.141983  litre. 

Pint  Q  gallon)  =  0.567932 

Quart  (i  gallon)  =  1.135864  " 

Imperial  gallon  (277.2738  cub.  in.)  =  4.54345797  litres. 
Peck  (2  gallons)  =   9.0869159  " 

Bushel  (8  gallons)  =  36.347664  " 


Sack  (3  bushels) 
Quarter  (8  bushels) 
Chaldron  (12  sacks) 


Milligramme 
Centigramme 
Decigramme 
Gramme 


Decagramme 

u 

Hectogramme 

Kilogramme 
(( 

Myriagramme 


=  1.09043 
=  2.907813 
=  13.08516 


hectolitre, 
hectolitres. 


Weights. 

0.015438395  troy  grain. 


0.15438395 

1.5438395 
15.438395 

0.643 

0.0321633 

0.0352889 
154.38395 

5.64 

3.21633 

3.52889 

2.6803 

2.205486 
26.803 
22.05486 


Quintal  metrique  = 
Tonne  = 


lOO 
1000 


"  grains, 
pennyweight, 
oz.  troy, 
oz.  avoirdupois, 
troy  grains, 
drachms  avoirdupois, 
oz.  troy, 
oz.  avoirdupois, 
lbs.  troy, 
lbs.  avoirdupois, 
lbs.  troy, 
lbs.  avoirdupois, 
kilog.  =   220.5486  lbs.  avoirdupois, 
kilog.  =  2205.486  " 


550 


VALUES  OF  FRENCH  AND  ENGLISH 


Diflferent  authors  give  the  following  values  for  the  gramme : — 
Gramme  =  15.44402   troy  grains. 
"        =  15.44242  " 
«        =  15.4402 
«        ==  15.433159  " 
«        =  15.43234874  « 


AVOIRDUPOIS. 

Long  ton  =  20  cwt.  =  2240  lbs.  =  1015.649  kilogrammes. 
Short  ton  (2000  lbs.)                  =   906.8296  " 
Hundred  weight  (112  lbs.)          =     50.78245  " 
Quarter  (28  lbs.)                       ==     12.6956144  " 

Pound  =  16  oz.  =  7000  grs.       =  453.4148  grammes. 
Ounce  =  16  dr'ms.  =  437.5  grs.  =     28.3375  " 

Drachm  =  27.344  grains  =      1.77108  gramme. 


TROY  (precious  metals). 


Pound  =  12  oz.  =  5760  grs. 
Ounce  =  20  dwt.  =  480  grs. 
Pennyweight  =  24  grs. 
Grain 


=  373.096  grammes. 
=     31.0913  « 

=  1.55457  gramme. 
=      0.064773  " 


APOTHECARIES'  (pharmacy). 

Ounce  =  8  drachms  =  480  grs.  =  31.0913  gramme. 
Drachm  =  3  scruples  =  60  grs.  =      3.8869  " 

Scruple  =•  20  grs.  =      1.29546  gramme. 


CARAT  WEIGHT  FOR  DIAMONDS. 

1  carat  =  4  carat  grains  =  64  carat  parts, 

"       =  3.2     troy  grains. 

"       =  3.273  " 

«       =  0.207264  gramme 

«  =0.212 

«  =  0.205  " 
Great  diversity  in  value. 

8 


WEIGHTS  AND  MEASURES,  ETC.  551 


Proposed  Symbols  for  Abbreviations. 


M — myria  — 

10000 

Mm 

Mg 

Ml 

K— kilo  — 

1000 

Km 

Kg 

Kl 

H — hecto  — 

100 

Hm 

Hg 

HI 

Ha 

D — deca  — 

10 

Dm 

Dg 

Dl 

Da 

Unit  — 

1 

metre — m 

gramme — g 

litre— 1 

are — a 

d — deci  — 

0.1 

dm 

dg 

dl 

da 

c — centi  — 

0.01 

cm 

eg 

cl 

ca 

m — milli  — 

0.001 

mm 

mg 

ml 

Km  —  Kilometre.  HI  =  Hectolitre.  eg  =  centigramme, 
c.  cm  =  Jra^  =  cubic  centimetre,  dm^  =  sq.  dm  =  square  deci- 
metre.   Kgm  =  Kilogrammetre.    Kg°  =  Kilogramme  degree. 


Celsius  or  Ccnti^rjido. 

T"  fi  h  r  G  n  li  c  i  t . 

—  15° 

+  5° 

—  12° 

—  10 

+  14 

—  8 

—  5 

+  23 

—  4 

0  melting 

+  32 

ice  0 

+  5 

+  41 

+  4 

4-  10 

+  50 

+  8 

+  15 

+  59 

+  12 

+  20 

+  68 

+  16 

+  25 

+  77 

+  86 

+  20 

+  30 

+  24 

+  35 

+  95 

+  28 

-f  40 

+104 

+  32 

+  45 

+  113 

+  36 

+  50 

+122 

+  40 

+  55 

+  131 

+  44 

4-  60 

+140 

4-  48 

4-  65 

+149 

+  52 

4-  70 

+158 

+  56 

+  75 

+167 

+  60 

4-  80 

+176 

+  64 

4-  85 

+185 

+  68 

4-  90 

+194 

+  72 

-f  95 

+203 

+  76 

+100  boiling 

+212 

water  +80 

4-200  ^ 
+300 

+392 

+160 

+572 

+240 

+400 

+752 

+320 

+500 

+932 

+400 

552         VALUES  OF  FRENCH  AND  ENGLISH 


1°  C.  X 
1°  C.  X 


C.  ==  1' 
=  1°  Ft. 
=  1°  R. 


1°  Ft. 


X  t 

1°  Ft.  X  f  ==  1 


=  1°  C. 
R. 


R.  X  f 
R.  X  f 


=1^ 


Ft. 
C. 


English. 


Calorie  (French)  =  unit  of  heat 

=  kilogramme  degree 
It  13  the  quantity  of  heat  necessary  to  raise  1°  C.  the  tempera- 
ture of  1  kilogramme  of  distilled  water. 

Kilogrammetre  =  Kgra  =  the  power  necessary  to  raise  1  kilo- 
gramme, 1  metre  high,  in  one  second.  It  is  equal  to  J-^  of  a 
French  horse  power.  An  English  horse  power  =  550  foot  pounds^ 
while  a  French  horse  power  =  542.7  foot  pounds. 

Ready-made  Calculations. 


No. 
of 
units. 

Inches  to 
centimetres. 

Feet  to 
metres. 

Yards  to 
metres. 

Miles  to 
Kilometres. 

Millimetres 
to  inches. 

1 

2.53995 

0.3047945 

0.91438348 

1.6093 

0.03937079 

2 

5.0799 

0.6095890 

1.82876696 

3.2186 

0.07874158 

3 

7.6199 

0.9143835 

2.74315044 

4.8279 

0.11811237 

4 

10.1598 

1.2197680 

3.65753392 

6.4373 

0.15748316 

5 

12.G998 

1.5239724 

4.57191740 

8.0466 

0.19685395 

6 

15.2397 

1.8287669 

5.48630088 

9.6559 

0.23622474 

7 

17.7797 

2.1335614 

6.40068436 

11.2652 

0.27559553 

8 

20.3196 

2.4383559 

7.31506784 

12.8745 

0.31496632 

9 

22.8596 

2.7431504 

8.22945132 

14.4838 

0.35433711 

10 

25.3995 

3.0479450 

9.14383480 

16.0930 

0.39370790 

No. 

Centimetres 

Metres  to 

Metres  to 

Kilometres 

Square  incbe.. 

of 

to  inches. 

feet. 

yards. 

to  miles. 

to  s^quare 

units. 

centimetrec 

1 

0.3937079 

3.2808992 

1.093633 

0.6213824 

6.45136 

2 

0.7874158 

6.5617984 

2.187266 

1.2427648 

12.90272 

3 

1.1811237 

9.8426976 

3.280899 

1.8641472 

19.35408 

4 

1.5748316 

13  1235968 

4.374532 

2.4855296 

25.80544 

5 

1.9685395 

16.4044960 

5.468165 

3.1089120 

32.25680 

6 

2.3622474 

19.6853952 

6.561798 

3.7282944 

38.70816 

7 

2.7559553 

22.9662944 

7.655431 

4.3496768 

45.15952 

8 

3.1496632 

26.2471936 

8.749064 

4.9710592 

51.61088 

9 

3.5433711 

29.5280928 

9.842697 

5.5924416 

58.06224 

10 

3.9370790 

32.8089'.i20 

10.936330 

6.2138240 

64.51360 

10 


WEIGHTS  AND  MEASUEES,  ETC. 


553 


No 

Squai'c  feet  to 

Scj,  yfirds  to 

Acres  to 

Srj,  mptrps 

of' 

sq.  metres. 

sq.  metres. 

hectares. 

centimetres 

to  sq.  feet. 

units. 

to  sq.  inches. 

1 

0.0929 

0.836097 

0.404671 

0.155 

10.7643 

2 

0.1858 

1.672194 

0.809342 

0.310 

21.5286 

3 

0.2787 

2.508291 

1.204013 

0.465 

32.2929 

4 

0.3716 

3.344388 

1.618684 

0.620 

43.0572 

5 

0.4645 

4.180485 

2.023355 

0.775 

53.8215 

6 

0.5574 

5.016582 

2.428026 

0.930 

64.5858 

7 

0.6503 

5.852679 

2.832697 

1.085 

75.3501 

8 

0.7432 

6.688776 

3.237368 

1.240 

86.1144 

9 

0.8361 

7.524873 

3.642039 

1.395 

96.8787 

10 

0.9290 

8.360970 

4.046710 

1.550 

107.6430 

No. 

Square  metres 

Hectares 

Cubic  inches 

Cubic  feet  to 

Cubic  yards 

of 

to  sq.  yards. 

to  acres. 

to  cubic 

cubic  metres. 

to  cubic 

units. 

centimetres. 

metres. 

1 

1.196033 

2.471143 

16.3855 

0.02831 

0.76451 

2 

2.392066 

4.9422S6 

32.7710 

0.05662 

1.52902 

3 

3.588099 

7.413429 

49.1565 

0.08494 

2.29354 

4 

4.784132 

9.884572 

65.5420 

0.11325 

3.05805 

5 

5.980165 

12.355715 

81.9275 

0.14157 

3.82257 

6 

7.176198 

14.826858 

98.3130 

0.16988 

4.58708 

7 

8.3722.31 

17.298001 

114.6985 

0.19819 

5.:^5159 

8 

9.568264 

19.769144 

131.0840 

0.22651 

6.11611 

9 

10.764297 

22.240287 

147.4695 

0.25482 

6.88062 

10 

11.960330 

24.711430 

163.8550 

0.28315 

7.64513 

No. 

^  Cubic 

Litres  to 

1 

Hectolitres  to 

Cubic  metres 

Cubic  metres 

of 

centimetres  to 

cubic  inches. 

cubic  feet. 

to  cubic  feet. 

to  cubic 

units. 

cubic  inches. 

yards. 

1 

0.06102 

61.02705 

3.5317 

35.31659 

1.30802 

2 

0.12205 

122.05410 

7.0634 

70.63318 

2.61604 

3 

0.18308 

183.08115 

10.5951 

105.94977 

3.92406 

4 

0.24411 

244.10820 

14.1268 

141.26636 

5.23208 

5 

0.30514 

305.13525 

17.6585 

176.58295 

6.54010 

6 

0.36617 

366.16230 

21.1902 

211.89954 

7.84812 

7 

0.42720 

427.18935 

24.7219 

247.21613 

9.15614 

8 

0.48823 

488.21640 

28.2536 

282.53272 

10.46416 

9 

0.54926 

549.24345 

31.7853 

317.84931 

11.77218 

10 

1 

0.61027 

610.27050 

35.3166 

353.16590 

13,08020 

11 


551      FKENCH  AND  ENGLISH  WEIGHTS,  ETC. 


No. 

Grains 

Ounces  avoir. 

Ounces  troy 

Pounds  avoir. 

Pounds  troy 

of 

to  grammes. 

to  grammes. 

to  grammes. 

to 

to 

units. 

kilogrammes,  kilogrammes. 

1 

0.064773 

28.3375 

31.0913 

0.4534148 

0.373096 

2 

0.129546 

56.6750 

62.1826 

0.9068296 

0.746192 

3 

0.194319 

85.0125 

93.2739 

1.3602444 

1.119288 

4 

0.259092 

113.3500 

124.3652 

1.8136592 

1.492384 

5 

0.323865 

141.6871 

155.4565 

2.2670740 

1.865480 

6 

0.388638 

170.0250 

186.5478 

2.7204888 

2.238576 

7 

0.453411 

198.3625 

217.6391 

3.1739036 

2.611672 

8 

0.518184 

226.7000 

248.7304 

3.6273184 

2.984768 

9 

0.582957 

255.0375 

279.8217 

4.0807332 

3.357864 

10 

0.647730 

283.3750 

310.9130 

4.5341480 

3.730960 

Pounds  per 

No. 

Long  tons  to 

square  inch  to 

Grammes  to 

Grammes  to 

Grammes  to 

of 

tonnes  of  1000  kilogrammes 

grains. 

ounces  avoir. 

ounces  troy. 

units. 

kilog. 

per  square 
centimetre. 

1 

1.015649 

0.0702774 

15.438395 

0.0352889 

0.0321633 

2 

2.031298 

0.1405548 

30.876790 

0.0705778 

0.0643266 

3 

3.046947 

0.2108322 

46.315185 

0.1058667 

0.0964899 

4 

4.062596 

0.2811096 

61.753580 

0.1411556 

0.1286532 

5 

5.078245 

0.3513870 

77.191975 

0.1764445 

0.1608165 

6 

6.093894 

0.4216644 

92.630370 

0.2117384 

0.1929798 

7 

7.109543 

0.4919418 

108.068765 

0.2470223 

0.2251431 

8 

8.125192 

0.5622192 

123.507160 

0.2823112 

0.2573064 

9 

9.140841 

0.6324966 

138.945555 

0.3176001 

0.2894697 

10 

10.156490 

0.7027740 

154.383950 

0.3528890 

0.3216330 

No. 
of 
units. 

Kilogrammes 

to  pounds 
avoirdupois. 

Kilogrammes 
to  pounds 
troy. 

Metric  tonnes 
of  1000  kilog 
to  iong  tons  of 
2240  pounds. 

Kilog.  per 
square  milli- 
metre to 

pounds  per 
square  inch. 

Kilog.  per 
square  centi- 
metre to 

pounds  per 
square  inch. 

1 

2.205486 

2.6803 

0.9845919 

1422.52 

14.22526 

2 

4.410972 

5.3606 

1.9691838 

2845.05 

28.45052 

3 

6.616458 

8.0409 

2.9537757 

4267.57 

42.67578 

4 

8.821944 

10.7212 

3.9383676 

5690.10 

56.90104 

5 

11.027430 

13.4015 

4.9229595 

7112.63 

71.12630 

6 

13.232916 

16.0818 

?.9(75514 

8535.15 

85.35156 

7 

15.438402 

18.7621 

6.8921433 

9957.68 

99.57682 

8 

17.643888 

21.4424 

7.8767352 

11380.20 

113.80208 

9 

19.849374 

24.1227 

8.861.3271 

12802.73 

128.02734 

10 

22.054860 

26.8030 

9.8459190 

14225.26 

142.25260 

13 


HYDROMETERS  AND  THERMOMETERS. 


555 


HYDROMETERS  AND  THERMOMETERS. 

An  areometer  is  a  convenient  glass  instrument  for  measuring  the 
densit}^  or  specific  gravity  of  fluids.  Areometer  and  hydrometer 
are  synonymous  terms,  the  first  being  derived  from  the  Greek 
words  apatoj,  rare^  and  /wsrpov,  measure;  and  the  latter  from  i^Sup, 
water,  and  /ustpov,  measure ;  hence  the  same  instrument  is  fre- 
quently denominated  both  hydrometer  and  areometer.  This  appa- 
ratus is  often  referred  to  throughout  this  work;  for  instance,  in 
speaking  of  alcohol,  or  lye,  their  strength  is  stated  as  being  of  so 
many  degrees  (17°  or  36°)  Baume,  that  is,  its  force  or  value  is  of 
that  specific  gravity,  corresponding  with  the  degree  to  which  the 
hydrometer  sinks  in  either  the  alcohol  or  alkaline  solution.  But, 
for  those  liquids  lighter  or  rarer  than  water,  viz.,  alcohol,  ethers, 
etc.,  the  scale  is  graduated  differently  than  for  the  heavier  or 
more  dense,  examples  of  which  are  the  acids,  saline  solutions, 
syrups,  and  the  like.  There  are  several  kinds  of  hydrometers; 
but  that  called  Baume's  is  the  most  used,  and  to  this  our  remarks 
are  applied. 

They  are  blown  out  of  a  piece  of  slender  glass  tubing,  and  of  the 
form  shown  by  Figs.  171  and  172;  A  being  tlie  stem  containing  the 


Fig.  171. 


Fig.  172. 


graduated  paper  scale,  B  the  bulb  portion,  and  D  the  small  globes 
containing  mercury  or  shot,  serving  as  ballast  to  maintain  the 
instrument  in  an  upright  position,  when  it  is  placed  in  a  liquid. 

The  graduation  is  accomplished  by  plunging  it  into  distilled 
water  of  58°  F.,  and  weighting  the  globe  with  shot  or  mercury, 
until  the  instrument  sinks  to  the  line  a,  which  is  its  zero  point. 
This  zero  point  thus  determined  is  to  be  marked  accurately  upon 

13 


556 


HYDROMETERS  AND  THERMOMETERS 


the  glass  or  its  accompanying  paper  scale,  and  the  instrument 
again  plunged  into  ninety  parts  of  distilled  water,  holding  in  solu- 
tion ten  parts  of  previously  dried  chloride  of  sodium  or  common 
salt.  The  point  to  which  it  sinks  in  this  liquid,  say  for  instance, 
is  then  also  marked  carefully  upon  the  scale,  and  rated  as  ten 
compared  with  its  zero  point.  The  interval  between  these  two 
points  is  then  spaced  olf  into  ten  equal  divisions,  according  to 
which  the  remainder  of  the  tube  is  graduated  so  that  each  degree 
is  intended  to  represent  a  density  corresponding  to  one  per  cent,  of 
the  salt. 

The  above  mode  of  graduating  refers  to  the  hydrometer  for 
liquids  denser  than  water,  but  that  for  the  liquids  rarer  than  water 
is  a  little  different  from  the  preceding  in  form,  and  necessarily  has 
a  modified  scale,  which  is  graduated  as  is  shown  by  Fig.  172.  The 
instrument  should  be  sufficiently  heavy  in  ballast  to  sink  in  a 
saline  solution  of  ten  parts  of  dried  chloride  of  sodium  in  ninety 
parts  distilled  water  to  the  bottom  of  .its  stem  a,  to  be  marked  as 
the  zero  of  the  scale. 

Now,  when  it  is  again  placed  in  distilled  water  alone,  it  floats  or 
sinks  to  a  point  somewhere  about  6,  which  is  to  be  the  ten  degree 
mark.  The  rest  of  the  stem  is  then  to  be  accurately  divided  into 
as  many  ten  degree  intervals  as  its  length  will  permit,  and  each 
subdivision  into  ten  uniform  smaller  degrees  or  intervals. 

As  it  would  be  troublesome,  and  with  many  impracticable,  to 
estimate  the  specific  gravities  of  their  liquids  in  a  sci- 
Fig.  173.  entific  way,  these  little  instruments  are  a  great  con- 
venience, for  by  taking  out  a  portion  of  the  fluid  to  be 
tested,  and  placing  it  in  a  glass  cylinder,  Fig.  173,  its 
degree  Baurae  may  be  ascertained  by  noting  the  point 
to  which  a  hydrometer  sinks  therein,  and  afterwards 
its  specific  gravity,  by  comparing  that  with  its  corre- 
sponding degree  in  the  table.  For  instance,  suppose 
the  h3"drometer  sinks  in  alcohol  to  35°,  then  its  specific 
gravity  is  0.8538,  and  this  agiiin  can  be  translated  into 
its  absolute  spirit  strength  by  comparison  with  any 
accurately  calculated  alcohol  tables.  So,  also,  if  a 
hydrometer  for  liquids  denser  than  water  sinks  in  lye 
to  26°,  it  denotes  that  the  lye,  as  will  be  seen  by  refer- 
ence to  Tiinnermann's  tables  (pages  259  and  261),  has 
a  specific  gravity  of  1.2268.  The  presence  of  foreign 
14 


HYDROMETERS  AND  THERMOMETERS. 


557 


matters  will  cause  the  hydrometer  to  give  a  false  indication,  and 
it  is,  therefore,  necessary,  when  lyes  contain  impurities,  to  follow 
the  directions  given  under  Alkalimetry,  to  ascertain  their  amount 
of  caustic  alkali.  When  the  lye  is  nearly  pure,  they  answer  satis- 
factorily ;  and,  indeed,  under  all  circumstances,  they  serve  very 
well  for  noting  a  progressive  increase  or  diminution  in  the  strength 
of  lyes  or  other  liquids.  The  temperature  of  the  liquid  should  be 
58°  to  60°  F.,  at  the  moment  of  testing  it. 

Thermometers. — The  thermometer  is  an  instrument  made  of 
glass  exclusivel}^,  when  intended  for  practical  purposes.  Fig.  IH 
shows  one  with  the  scale  of  Fahreidieit,  graduated  on 
the  glass,  so  that,  when  having  been  dipped  in  liquids, 
it  ma}^  be  easily  cleansed.  It  derives  its  name  from 
two  Greek  words,  gfpiwoj,  vmrm^  and  |Wfrpo^,  measure^ 
and  is,  as  its  title  indicates,  a  measurer  of  the  variation 
of  temperature  in  bodies.  The  principle  upon  which 
it  is  constructed,  "is  the  change  of  volume  which  takes 
place  in  bodies,  when  their  temperature  undergoes  an 
alteration,  or,  in  other  words,  upon  their  exi)ansion." 
As  it  is  necessary,  in  the  construction  of  thermometers, 
that  the  material  used  to  measure  the  change  of  tem- 
perature shall  be  of  uniform  expansion,  and  with  a 
very  distant  interval  between  its  freezing  and  boiling 
point,  as  fulfilling  these  requisites  better  than  any 
other  body,  metallic  mercur}^  is  generally  used.  There 
are  several  different  theruiometrical  scales,  all  con- 
structed upon  the  same  principle,  but  varying  in  their 
graduation ;  the  boiling  and  freezing  points  of  each, 
though  corresponding  in  fact,  being  rei)resented  by 
different  numbers.  The  Fahrenheit  scale  is  most  used 
in  this  country;  that  of  Celsius,  called  the  Centigrade, 
in  France  and  the  Continent  generally,  except  Spain 
and  German3',  where  Reaumur's  scale  is  prefei-red. 
The  relation  between  the  three  scales  is  shown  1)3^  Fig.  175.  The 
Fahrenheit  scale  is  most  convenient,  because  of  the  lesser  value 
of  its  divisions. 

In  the  graduation  of  the  scale,  it  is  onl}^  necessary  to  have  two 
fixed  determinate  temperatures,  and  for  these  the  boiling  and 
freezing  points  of  water  are  universall}'  chosen.  The  scales  can 
be  extended  be3'ond  either  of  these  points,  by  continuing  the 

15 


558 


HYDROMETERS  AND  THERMOMETERS. 


graduation.  Those  degrees  below  zero  or  0°  have  the  minus  ( — ) 
prefixed,  to  distinguish  them  from  those  above;  thus,  55°  F.  means 
fifty-five  degrees  above  zero,  Fahrenheit's  scale,  and  — 9°  C,  nii?e 


Fig.  175. 


degrees  below  zero.  Centigrade  scale.  The  thermometers  for 
general  use  very  seldom,  however,  extend  either  way  beyond  the 
boiling  and  freezing  points  of  water,  but  for  manufacturers'  use 
they  are  graduated  sometimes  to  400°  or  600°. 

Centigrade  and  Fahrenheit — In  the  Fahrenheit  thermometer 
the  number  0°  on  the  scale  corresponds  to  the  temperature  of  a 
mixture  of  salt  and  ice — tlie  greatest  degree  of  cold  that  could  be 
artificially  produced  when  the  thermometer  was  oriijinally  intro- 
duced ;  32°  (freezing  point)  corresponds  to  the  temperature  of 
melting  ice;  and  212°  to  the  temperature  of  pure  boiling  water — 
in  both  cases,  under  the  ordinary  atmospheric  pressure  of  14.7 
pounds  per  square  inch.  Each  division  of  the  (this)  thermometer 
represents  1°  Fah.,  and  between  32°  and  212°  there  are  180°.  In 
the  Cent,  thermometer,  used  universally  in  scientific  investigations, 
1°  corresponds  to  melting  ice,  and  100°  to  boiling  water.  From 
the  freezing  to  the  boiling  point  there  are  100°. 

The  accompanying  table  shows  the  relation  of  the  Centigrade 
and  Fahrenheit  thermometer  scales,  5°  C.  being  equal  to  9°  F., 
because  the  interval  between  the  freezing  and  boiling  points  of 
water  is  divided  into  100  and  180  equal  parts,  and  these  numbers 

16 


HYDROMETERS  AND  THERMOMETERS. 


559 


are  respectively  multiples  of,  or  20  times  5  and  9.  If  the  super- 
fluous 32°  on  the  F.  side  were  disposed  of,  the  mutual  translation 
of  the  scales  would  be  simple,  since  the  two  units  are  to  each 
other  inversely  as  the  number  of  them  in  any  given  range. 

To  reduce  F.  above  melting  ice  to  terms  of  C,  32^  must  first  be 
subtracted  from  the  given  F.  temperature,  then  multiply  the  re- 
mainder by  f ;  the  product  will  be  the  C.  term  for  the  given  tem- 
perature; and  conversely  divide  C.  by  f  and  add  32  to  translate 
C.  into  F.;  to  prove  the  work,  read  the  terms  across  the  diagram 
in  the  table.  Below  melting  ice,  the  same  rules  as  given  above 
apply,  except  that  where  32  is  added  above,  it  should  be  subtracted 
here,  and  vice  versa. 

In  the  columns  at  the  right  hand  of  each  diagram  in  this  table, 
are  found  the  approximate  steam  pressures  per  square  inch,  due 
to  the  adjoining  indications  of  temperature.  Tiie  pressure  is 
expressed  in  pounds  and  in  atmospheres. 

The  high  pressures  are  obtained  from  the  several  authors  who 
have  deduced  and  tabulated  them  from  experiments  and  formulas 
of  Regnault  and  others ;  and  being  hypothetical,  accuracy  is  not 
claimed  for  them. 

17 


5(30 


HYDROMETERS  AND  THERMOMETERS. 


COMPARISON  OF  CENTIGRADE  AND  FAHRENHEIT  SCALES,  AND  APPROX- 
IMATE  STEAM  PRESSURE  IN  POUNDS  AND  ATMOSPHERES 
PER  SQUARE  INCH  DUE  TO  THE  TEMPERATURE. 


Thermometer. 


Steam. 
Non-condensing  Engine. 


Fahr. 


500 
491 
482 
473 
464 
455 
446 
437 
428 
419 
410 
401 
392 
383 
374 
365. 
356 
347 
338 
329 
320 
311 
302 
293 
284 
|275 
266 
257 
248 
239 
230 
221 


Pres.  per 
gauge, 
lbs. 


665 
610 
560 
515 
472 
430 
390 
354 
321 
290 
262 
235 
211 
188 
167 
148 
131 
115 
100 
85 
73 
63 
55 
45 
37 
30 
25 
19 
14 
10 
6 
3 


Total  Press. 


Lbs. 


680 
625 
575 
530 
487 
445 
405 
369 
336 
305 
277 
250 
226 
203 
182 
163 
146 
130 
115 
100 
88 
78 
70 
60 
52 
45 
40 
34 
29 
25 
21 
18 


Atmos. 


46. 

42. 

39. 

36. 

33. 

30. 

27.5 

25. 

23. 

20.7 

18.8 

17. 

15.3 

13.8 

12.4 

11.1 

9.9 

8 

7, 

6.8 

6. 

5. 

4. 

4.1 

3.5 

3 

2. 

2 

1.9 
1.6 
1.4 
1.2 


Thermometer. 


Centi. 


100 
95 
90 
85 
80 
75 
70 
65 
60 
55 
50 
45 
40 
35 
30 
25 
20 
15 
10 

5 

0 

—  51 

—10 
—15 
~£0 
—25 
—30 

—  35 
-40 
—45 


Fahr. 


1212 

203 
|l94 

185 

L76 

167  o 

o 

1149  o 

o 

1140  I 

131  1 

122 

113 

il04 

95 

86 

77 

68 

59 

50 

41 

32 

23 

14 

5 
0 

—  4 
—13 
—22 
—31 
—40 
-49 


Steam. 
Condensing  Engine. 


Press,  per 
gauge. 


Back  Press. 


Vacuum,  effective 


Lbs.  Atmos. 
1. 


14.7 


Gauge. 


H 

12i 
15f 

m 

20^ 

22 

24 

25 

26 

26i 

27f 

28| 

29 


Lbs.* 


4.7 
6.2 
7.7 
9.1 
10.2 
11. 
11.9 
12.4 
12.9 
13.3 
13.6 
13.8 
13.9 


12. 

10. 
8.5 
7. 
5.6 
4.5 
3.7 
2.8 
2.3 
1.8 
1.4 
1.1 
.9 
.8 


0.85 

0.7 

0.6 

0.5 

0.4 

0.3 

0.2 

0.2 

0.1 


*  To  be  added  to  the  pressure 
indicated  by  steam  gauge  to 
get  total  pressure  on  piston. 


M.  T.  Mines  of  Brittany. 

500  It.,  .  .  .  59  F. 
Hydrochloric  Ether  boils,  52  F. 

Max.  density  of  water,  f^^Q' 

Melting  Ice,  .  32F.  =0C. 
Blood  freezes,  ,  .  £5  F. 
Castor  Oil  freezes,  .  21  F. 
Spirits  of  turpentine 


freezes. 


Brandy  freezes, 


14  F. 


-7F. 


Mercury  freezes,  .  —40  F. 
Sulphuric  Acid  (1.641) 

freezes,       .      .  —45  F. 

Greatest  artificial 

cold,    .    -166  to -220  F. 


Absolute  cold, 


( —450.4  F. 
•■)— 213.  C. 


18 


AMMONIACAL  PROCESS  FOR  SODA  ASH. 


561 


Note. — Soda  Ash  by  the  Ammoniacal  Soda  Process,  Much  at- 
tention has  been  attracted  to  a  very  pure  soda  obtained  by  this 
process,  which  was  really  not  perfected  in  a  practical  way  until 
1878.  This  process  is  the  only  one  that  has  successfully  competed 
with  that  of  Leblanc,  and  consists  of  the  conversion  of  ammonium 
carbonate  and  sodium  chloride  (common  salt)  into  sodium  bicarbo- 
nate and  ammonium  chloride.    The  equation  is — 

NaCl  +  (NHJ  HCO3  =  NH^Cl  +  NaHC03. 

The  latter  two  salts  are  easily  separated,  as  sodium  bicarbonate 
is  ver}^  slightly  soluble  in  a  solution  of  sal  ammoniac  and  separates 
in  the  form  of  crystals.  Of  course  the  ammonium  carbonate  must 
always  be  regenerated. 

Mr.  Hemming  obtained  a  patent  in  England  in  1838  for  this 
process,  and  it  attracted  much  attention  in  France,  Germany,  and 
Austria,  and  was  tried  in  numerous  places,  and  became  the  subject 
of  many  patents  in  each  country,  but  it  seems  that  it  is  due  to  the 
untiring  perseverance  of  Mr.  Ernest  Solvay,  of  Belgium,  that  the 
process  has  been  practically  carried  out  to  a  paying  enterprise. 
He  has  several  patents  in  both  England  and  Germany,  and  the  last 
is  as  late  as  18tt,  and  since  then  several  other  chemists  have  made 
some  slight  improvements  upon  his  methods. 

Soda,  made  by  this  process,  is  now  an  article  of  commerce,  and 
is  much  used  by  the  soap  manufacturers  of  Europe,  and  by  a  few 
in  this  country,  and  seems  to  have  given  entire  satisfaction,  as  it 
should,  as  it  is  much  more  free  from  admixture  of  other  salts,  and 
consequently  must  produce  a  better  soap  with  less  labor  than  the 
sodas  by  the  old  processes.  In  appearance  it  differs  very  much 
from  the  ordinary  crj'stallized  carbonate  of  soda,  being  in  the  state 
of  amorphous  lumps  of  various  sizes  combined  with  some  powder. 
We  add  this  note  to  call  the  attention  of  the  alkali  as  well  as  the 
soap  manufacturer  to  this  valuable  soda. 


36 


INDEX. 


Acid,  normal  liquor,  365,  368,  369 
Adamantine  candles,  532 
Adulteration  of  attar  of  roses,  450,  451 

of  black  poppy  oil,  141 

of  castor  oil,  142 

of  cocoa-nut  oil,  142 

of  herapseed  oil,  141 

of  linseed  oil,  141 

of  neat's-foot  oil,  142 

of  oil  of  sweet  almonds,  140 

of  oleic  acid,  142 

of  olive  oil,  140 

of  palm  oil,  142 

of  rapeseed  oil,  141 

of  sesame  oil,  141 

of  the  fatty  bodies,  140-151 

of  volatile  oils.  443 
Agricultural  soap,  389 
Aigues-Mortes,  soda  of,  43 
Alkali  and  soap  trades,  history  of,  19- 
25 

Alkali  in  soaps,  determination  of,  352- 
357 

Alkali,  manufacture  of,  in  Germany, 
22,  23 
normal,  184,  185 
trade  of  England,  22 
Alkalies,  26-68 

carbonated,  337,  338 

for  toilet  soaps,  401 

importance  of  a  knowledge  of  con- 

stituents,  166 
nitric   acid  required  for  mixed, 
189,  190 

of  commerce,  never  pure,  166,  248 

pulpliuretted,  338 
Alkalimetric  test  of  lyes,  255 
Alkalimetry,  166-192 
Alkalimetry,  bases  of,  179-184 
Alkaline  liquor,  normal,  365,  369,  370 
Alkalumino-silicic  soap,  333 
Almond,  bitter,  oil  of,  444-446 

grain  soap,  296 


Almond  oil,  97,  98,  108 

shaving  cream,  426 
Altenburge's  rosin  soap,  383 
Alum  for  filling  soft  soaps,  319 

soap,  419 
Ambergris,  453,  455 

soap,  412 
Ambrosial  shaving  cream,  426 

soap,  412 
American  measures,  549 

potash,  red,  35-37 
Ammonia,  60 

action  on  oils,  74 
Ammoniacal  process  for  soda  ash,  561 
Ammoniated  soap,  388 
Analyses  of  soaps,  table  of,  363 
Analysis  of  lime,  194 

of  soaps,  351-379 

volumetric,  167,  1 68 
Anhydrous  carbonate  of  soda  193 

potash,  table  of  specific  gravity 
and  hydrometric  degrees,  259 

soda,  table  of  specific  gravity  and 
hydrometric  degree,  361 
Animal  fats,  75-97 

Apothecaries'  and  imperial  measures, 
relative  value  of,  545 
measure  in  apothecaries'  weight, 
value  of,  546 
in  avoirdupois  weight,  value 
of,  546 
weight,  545,  550 

in     apothecaries'  measure, 
value  of,  546 
Apparatus  for   boiling  soap  by  sur- 
charged steam,  219-221 
Apple-seed,  oil  of,  98 
Application  of  soaps,  195,  196 
Aqueous  solutions  of  soaps,  365,  366, 

367.  368 
Artificial  grain  soap,  320,  321 

light  from  the  flame  of  a  caudle, 
principles  of,  460 


564 


INDEX. 


Artificial  — 

salted  eoda,  52-54 
wax-candles,  5:^2,  538 
Ashes  and  potash  in  different  vegeta- 
bles, table  of,  30 
boiling  with,  312,  313 
from  tnrtar,  37 

in  different   parts    of  the  same 

plant,  30 
in  vegetables,  29 
leaching  or  washing,  34,  3o 
Ash-fat,  96 

pan,  205 
Ashley's  moulding  machine,.  513 
Assajs  of  oils,  143-147 
Attar  of  rose,  449,  451 

adulteration  of,  450,  451 
Avocado  oil,  1 1 1 
Avoirdupois  weight,  545,  550 

in     apothecaries'  measure, 
value  of,  54G 

Balsam,  Peruvian,  454 
B^imhuk  butter,  104 
Barilla,  mixed,  44 

salted,  44 
Barring  machine,  Van  Haagan's,  239 
Bases,  neutralized    by  norm;il  nitric 
acid,  181-184 

of  alkalimetry,  179-184 
Basins  of  brick  or  stone,  205 
Bassia  oil,  107 

Baum^  hydrometer,  167,  655 
Beech,  oil  of,  98 
Beechnut  oil,  97,  115,  116 
Beef  marrow  soap,  420 

tallow  for  candles,  458 
Beeswax,  125,  484,  485 

bleaching,  485 

melting  point  of,  125 
Beet-root  molasses,  potash  from,  38,  39 
Belgian  soft  soap,  388 
Belgium,  iMarseilles  soap  made  in,  275 
Belladonna  seeds,  oil  of,  124 
Belmont  sperm  candles,  532 

wax  candles,  532 
Bennett  &  Gibbs's  process,  347-350 
Ben  oil,  97,  110 

Benzine  for  dissolvitig  fats,  132 
Benzoic  acid  soap,  419 
Benzoin  soap,  412 
Bergaraot,  oil  of,  443,  444 
Bertagnani  on  the  detection  of  adulte- 
ration of  oil  of  bitter  almond,  444 
Berzelius,  19 
Bicuyda  wax,  126 
Bisam,  or  musk,  453 
Bitter  almonds,  oil  of,  444-446 
Black  poppy  oil,  adulteration  of,  141 


Bleaching  of  palm  oil,  101-104 

soap,  296,  384 

stearic  acid,  518 
Bogardus's  eccentric  mill,  229 
Boilers,  206 

Boiling,  melting,  and  freezing  points  of 
different  substances,  560 
of  soft  soap,  317,  318 
pans  or  caldrons,  224,  225 
soap  by  surcharged  steam,  219- 
221 

in  France,  200.  201 
toilet  soaps  by,  392-399 
with  wood  ashes,  312 
Bole  Armenian,  for  marbling  soap,  272 
Bone  fat,  92,  93 

soda  soap  made  with,  92 
soft  soap  of,  92 
soap,  334,  335 
Bones,  falsification  of  wax  with,  150 
for  making  soaps,  manipulation  of 

with  muriatic  acid,  335 
treatment  of,  to  obtain  the  fat,  92 
of,  with  caustic  lye,  335 
Boomer   &   Boschet's   elbow  presses, 

467-469 
Borax  soap,  305 

powder,  387 
soft  soap,  386 
toilet  soap,  419 
Bordhardt's  herb  soap,  420 
Bougies,  large,  for  churches,  526 
l)0uquet  soap,  410 

Braconnet,  researches  of,  on  fatty  bod- 
ies, 458 
Bran  soap,  384,  419 
British  Imperial  Measures,  549 
Bromine  soap,  419 

Buchner's   method   to  determine  the 

value  of  sebacic  acid  in  soap,  359 
Buchner's  table  of  the  soap  and  glyce- 
rine furnished  by  fats,  359 
Burette,  the,  168-172 
Butter,  90,  91 
Butter,  cocoa,  123-124 
Butter,  composition  of,  91 
Butter,  Goa,  124 

of  nutmegs,  122 

composition  of,  122 
proportions  of  the  injmediate  prin- 
ciples of,  91 
substance  yielded  by,  when  washed 
in  warm  water,  91 

Cabbage-seed,  oil  of,  98 
Caesium,  60 

oxides  of,  156 
Cailletet,  process  of  analysis,  365-370 
Caking  machines,  241,  242,  428-430 


INDEX. 


565 


Calcination  of  soda,  50 

Calculations  of  weights  and  measures 

ready  made,  552-554 
Cameliua  oil,  97,  98,  116 
Camphor  ice  soap,  419 
Camp's  moulding  wheel,  518,  514 
Canada  snakeroot,  oil  of,  452 
Candle-flame,  description  of,  4r)0-4(j2 
Candle  manufacture,  a  scientific  indus- 
try, 459 
to  burn  on  water,  536 
Candles,  advantages  of,  for  illumina- 
tion, 457 
•  by  steam,  520-522 
composite  and  patent,  532-530 
decorated  and  colored,  587-542 
dipped,  494-500 

Gay-Lussac  and  Chevreul  patents, 
458 

history  of,  457 
manufactures  of,  457-542 
materials  for,  457 

for,   and   their  preparation, 
463-487 
moulded,  501-527 
moulding,  stearic  acid,  517,  518 
polishing  and  finishing  of,  528-581 
principles  of  light  from  the  tt  ime 

of,  4G0 
stearine,  51 5-517 
tallow,  early  manufncture  of,  457 
Capacity,  measures  of,  548 
Carapa  oil,  124 
Carat  weight,  550 
Caraway  seed  oil,  447 
Carbadinic  musk,  453 
Carbolic  soap,  418 
Carbonate  of  lime,  180 
of  potash,  89,  41 

and  carbonate  of  soda,  table 

of  mixture  of,  189,  19i) 
to  change  into  caustic  alkali, 
249 

of  soda  and  carbonate  of  potash, 
mixture  of,  189,  190 
crystallized,  55-57 
for  filling  soft  so;ips,  819 
for  rosin  soaps,  304 
refined,  54,  55 

to  change  into  caustic  soda, 
250 

Carbonated  alkalies,  337,  388 
Carbonates  of  alkali  never  pure,  249 

of  soda,  table  of,  198 
Carbonic  acid,  to  remove  from  lyes,  248 
Carnalite,  28 
Carnauba  wax,  126,  485 
Carny,  46,  47 

Cashmere  soap,  perfume  for,  442 


Cassia  oil,  452 
Castile  soap,  274-276 

formulas  for,  273,  274 

from  cotton-seed  oil,  296-300 

white,  281 
Cast-iron  kettles,  212,  213 
Castor  oil,  97,  98,  113 

adulteration  of,  142 

soap,  419 
Cauldrons  or  boiling  pans,  224,  225 
Caustic  lime  never  pure,  249 

lyes  of  soda,  248 

potash,  Liebig's  experiments  on, 
251 
lye,  248 
salts  of  soda,  57-59 
soda,  analysis  of,  58 
for  rosin  soap,  304 
from  cryolite,  60 
table  of  specific  gravity,  and 
per  cent,  of,  59 
solution  of  crystals  of  soda,  396 
Cellars,  205,  207 

Celsius  or  Centigrade  thermometer,  551 , 
557-560 

Centigrade  orCelsius  thermometer,  551, 

557-560 
Centrifugal  mill  for  tallow,  470 
Cerophatie  bougies,  532 
Chamby,  apparatus  of,  for  extracting 

tallow,  77 

Chemical    equivalents    applicable  to 
soap,  152-155 

Chevreul  and  De  Milly,  importance  of 
their  researches  upon  the  indus- 
try of  candles,  4()0 
and  Scheele,  researches  of,  on  fatty 

bodies,  69 
importance  of  his  discoveries,  28 
on  composition  of  butter,  91 
on  the  eff'ects  of  saponification  on 

fats,  156 
patent  for  candles,  458 
researches  of  on  fatty  bodies,  458 
theory  of  saponification  of,  17 

Chimney,  206 

Chimney,  general,  204 

Chinese  wax,  485 

Churches,  bougies  for,  526 

Cierges  for  churches,  524 

CinnamoJi,  oil  of,  452 

Cisterns  in  masonry,  205,  207 

Civet,  454 

tincture  of,  454 

Clay  for  filling  soft  soaps,  819 

Clear  boiling,  269 

boiling  or  coction,  277,  278 

Cloves,  oil  of,  448 

Cocoa  butter,  97,  123,  124 


566 


INDEX. 


Cocoa-nut  kernels,  oil  in,  105 
oil,  24,  97,  105-107 
action  of,  in  saponification,  lOH 
adulteration  of,  142 
for  candles,  459 
for  rosin  soaps,  286 
for  toilet  soaps,  392.  897 
has  property  of  making  soaps 
capable  of  retaining  water, 
304 

in  soaps,  salt  which  they  will 

bear,  325 
odor  of,  106 

power  to  absorb  water,  325 
soap  by  cold  process,  303 
soaps,  common,  326 
the  peculiar  acids  of,  70 
white  soap  from,  398,  399 
oils,  melting  points  of,  105 
Cochineal  tincture.  177-179 
Coction,  277,  278,  394,  395 
Cod-liver  oil,  95-97 

oil,  composition  of,  96 
Coffee's  siphon,  228 
Cold,  absolute,  560 
cream  soap,  409 
greatest  artificial,  560 
process,  for  toilet  soaps,  392 
toilet  soaps  by,  400-408 
soaps,  302 

lyes  for,  304 
mechanical  aid  in,  302 
Coleseed  oil,  97,  98,  109 
Cologne,  fat  lost  in  tlie  soap  consumed 
in,  139  • 

Colophony,  action  of  train  oil  on,  96 

or  rosin,  126-129 
Coloration  taken  by  different  oils,  146, 
147 

Colored  candles,  tapers,  etc.,  537-542 
Coloring  toilet  soaps,  439 
for  toilet  soaps,  404 
soaps,  428 
Colors  for  candles,  537,  538 

for  coloring  candles,  which  desir- 
able  and   which  objectionable, 
537,  538 
Colza  oil,  116 

Combustion  of  plants  in  furnaces  for 

potash,  33,  34 
Commercial  red  oil,  117-121 
Common  cocoa-nut  oil  soaps,  326 

filled  rosin  soaps,  326 
Composite  and  patent  candles,  532-536 
Composition  candles,  533 

of  commercial  potashes,  39,  40 
Consistency  of  soap  affected  by  the 
melting  points  of  the  fats,  163 

to  give  to  soap,  280 


Continuous  wick  machine,  512,  513 
Coops,  melting,  for  tallow,  81 
Copper  soap,  156 
Cornmeal  soap.  419 

Cotton-seed  oil,  97,  98,  111-113,  296- 
300 

castile  soap  from,  296-300 
extraction  of.  111 
for  toilet  soaps,  392 
saponified,  297 
Country  soap,  385 
Crackling  soap,  334 
Cream  shaving,  424 
Creme  d'Ambrosie,  426 
Creasote  soap,  419 
CrotOD-oil  soap,  419 
Crown  soap,  Etiglish,  first  quality,  323 

second  quality,  323 
Crutching  machines,  243-246 
Cryolite,  60 

caustic  soda  from,  60 
Ciystallized  carbonate  of  soda,  55-57 
Ci  ystals  of  soda,  55-57 

caustic  solutions  of,  396 
Cucumber  soap,  415 
Culinary  salt,  use  of,  for  separation, 

267,  268 
Curd  or  grain  soaps,  266-284 
soap,  281-284 
tallow  soap,  309-313 
Cutter,  Ralston's,  243 
(Jutting  of  the  pan,  283,  310,  311 
of  wicks,  machines  for,  490,  491 
operation,  238 
table  for  soaps,  430,  431 
Cylinders  for  mixing  in  alkalimetry, 
176 

Dalton's  table  of  contents  of  soda  in 
lye,  261,  262 
of  potash  contents  of  lye,  259, 
260 

D'Arcet,  method  of  extracting  tallow, 
75 

methods,  341-346 

on  the  extraction  of  potash  from 
the  ashes  of  horse-chestnuts,  29 
Davis's  alkaluraino-silicic  soap,  333 
Decalcomanie,  539 

Decorated  and  colored  candles,  tapers, 
night  lights,  etc.,  537-542 
candles,  538-540 
base  of,  539 
Decoration  of  candles,  styles  for,  539, 
540 

Deiss,  application  of  sulphuret  of  carbon 

to  otfall  fats  by,  131 
Deite,    Dr.,  formula    for  transparent 

soap,  305 


INDEX. 


567 


De  Milly,  manufacture  of  stearine  by, 
459 

De  Milly's  process  of  saponification  by 
lime,  477,  478 
by  sulphuric  acid,  479 

Detergent,  17 

Determination  of  amount  of  alkali  in 
soaps,  352-859 
of  soap  as  to  admixtures,  302 
of  the  amount  of  sebacic  acid  and 
rosin  in  soap,  857,  359-3G1 
Diaphanous  candles,  533 
Dipped  candles,  494-500 

apparatus  for  making  symme- 
trical, 495 
wicks  for,  494 
Dipping  of  candles,  machines  for,  495- 
497 

Disinfectant  soap,  419 
Distilling  apparatus  for  use  of  sur- 
charged steam.  481 
Domestic  soft  soap,  386 
Dresden  palm  soap,  383 
Drying  oils,  71 

room,  207,  208 

manner  of  using,  210 
temperature  of,  208 
with  warm  air,  208-21 1 
soap  in  rooms  heated  by  stoves. 
209 

Dry  melting  of  tallow,  81 
Dubrunfault,  M.,  process  for  extracting 

potash  from  beet-root  molasses, 

38 

saponification  by,  479 
Dumas,  46 

Dunn's  silicic  soap,  381,  332 
Dyeing,  soaps  for,  195 

Earth-nut  oil,  98 

Eccentric  mill,  Bogardus',  229 

Edinburgh  wheel  for  candles,  408,  499 

Egg  yolk  soap,  419 

Egypt,  natron  of,  44,  45 

Elaidic  acid,  486 

Elaidin  soap,  288-296  - 
soft  soap,  321,  322 

Elain  soaps  from  oleic  acid,  119 

Elaine,  what  it  is,  70 

Elder-flower  soap,  411 

perfumes  for,  442 

Emollient  properties  of  brown  Windsor 
soap,  what  due  to,  406 

Empatage,  276 

England,  alkali,  trade  of,  22 
candles  used  in,  460 
soap  manufacture  in,  21,  22 

English  crown  soap,  first  quality,  323 

Epicea  seeds,  oil  of,  98 


Erasive  soap,  385 

Essences  for  perfuming  toilet  soaps,  440 
Essential  oils  for  perfuming,  44(),  443- 
455 

Establishment  of  a  soap  factory,  197- 
247 

Estimation  of  soda  in  lyes  of  potash, 

185-193 
Extempore  soaps,  400 

and  other  soaps,  301-313 
Extraction  of  potash,  32-41 
Euphorbium,  oil  of,  98 
% 

Fabrication  of  artificial  soda,  history  of, 
45-48 

of  soaps,  248-336 
Factory  at  St.  Quen,  France,  199-202 

building,  203 

establishment  of  a  soap,  197-249 
Fahrenheit  thermometer,  551,  557-560 
Falsification  of  lard,  148 

of  tallows,  149 

of  waxes,  150,  151 
Faraday,  process  of  saponification,  480 
Fat,  bone.  92,  93 

Fuller's  utilization  of,  132-139 

glue,  92,  98,  94 

horse,  93 

in  pyroligneous  aeid,  71 
kitchen,  94 

lost  in  the  soaps  consumed  in  Co- 

logne,  139 
oils,  71 

or  oil,    none  used    alone,  which 

nuikes  a  faultless  sojip,  262 
wool,  utilization  of,  182-139 
Fats  and  lyes,  proportions  of,  263-266 
and  oils,  68-124 

advantages   in   mixing,  262, 
268 

decomposition  of,  68 
ethers  of  glycerine,  157 
impurities  in,  262 
of  vegetable  origin,  97-124 
used  in  the  manufacture  of 
soaps,  69 
benzine  for  dissolving,  132 
chiefly  used  for  candles,  458 
decomposition  of,  72 

of  by  lime,  472-477 
decomposed  when  distilled,  72 
dissolved  by  sulphuret  of  carhon, 
182 

expand  in  increase  of  temperature, 
71 

found  in  animals  and  vegetables, 

great  variety  of,  74,  75 
in  chloroform,  71 
in  ether,  71 


668 


INDEX. 


Fats- 
influence  of  sulphuric  acid  on,  73 
in  heated  alcohol,  71 
in  sulphuret  of  carbon,  71 
in  volatile  oil,  71 
lime  in,  92,  93 

liquid  or  oils,  when  they  become 

solid,  69 
of  animal  origin,  75-97 
off"al,  yield  of  by  means  of  sul- 
phuret of  carbon,  131,  182 
phosphorescent  in  the  dark,  72 
saponification  of,^by  means  of  car- 
bonated alkalies,  337,  838 
by  sulphuretted  alkali,  338 
solid,  when  they  become  liquid,  69 
specific  lubricity  of,  71 

gravity  of,  71 
vegetable  and  animal,  composition 
of,  70 

■waste  of,  in  cloth  factories,  132 
what  soluble  in,  7 1 
Fatty  acids,  behavior  of,  when  conibined 
with  alkaline  bases,  27 
acids,  27 

report  on,  480,  481 
bodies,  adulteration  of,  140-150 
importance  of  in  industries, 
69 

rags,  treatment  of,  by  sulphuret  of 
carbon,  132 
Fecula,  falsification  of  wax  with,  151 
Fennel,  oil  of,  446 

Fetid  vapors  of  tallow,  destroying,  78- 
86 

Fig  soap,  320,  387 
Filled  rosin  soaps,  common,  326 
soaps,  325-336 

formulas  for,  335,  386 
Filling,  applicable  to  certain  soaps,  326 
in  toilet  soaps,  401 
or  grinding  of  soap,  271,  272 
Finishing  and  polishing  of  candles,  528- 
531 

soap  cakes,  438,  439 

soaps,  428 
Fireplnce,  204-206 
Fish  oils,  95 
Fitted  soap,  201 
Fitting,  279,  281,  395 

D'Arcet's  views  on,  842 

olein  soap,  292-294 
Fixed  oils,  98 

Flame,  cause  of  shape  of,  460 

of  a  candle,  description  of,  460- 
462 

Flasks,  measure  for  alkalimetry,  175, 
176 

Floating  soaps,  421 


Flour,  falsification  of  wax  with,  151 
Foundation  of  kettles,  207 
Frames  for  dipping  candles,  500 

of  brick  and  cement,  205 

of  iron,  231,  233 

of  masonry,  230,  231 

of  wood,  207,  233-236 

soap,  230-236 

soap,  German,  235 

Whittakei's  soap,  232,  283 
France,  candles  used  in,  460 

establishment  of  the  soap  industry 
in,  20 

soap  statistics  of,  24 
Frangipanni  soap,  411 
Frankfort  black,  for  marbling  soap,  272 
Freezing,  melting,  and  boiling  points  of 

difl'ererit  substatices,  560 
French  and  English  weights  and  meas- 
ures, relative  values  of,  547-^54 

apparatus  for  moulding,  521 

scouring  soap,  385 

soap  factories,  199-208 

toilet  soaps,  names  of,  417 

weights,  549 
Fucus  maritimus,  43 
Fuller's  fat,  utilization  of,  132-139 
Fulling,  soaps  for,  195 
Furnace  for  candles,  498 
Furnaces  for  heating  kettles,  213-215 

Gaduin,  96 

Galam  butter,  104,  121 

Gallipoli  oil,  107,  108 

Gaultheria  or  wintergreen  oil,  446,  447 

GayLussac,  19 

analysis  of  soda  by,  42 

base  of  for  alkalimetry.  179 

patent  for  candles,  458 
Germany,  manufacture  of  alkali  in,  22 

soap  manufacture  in,  22 
statistics  of,  24 
Gentele,  formula  for  soft  soaps  with 

soda,  315,  316 
Geranium  oil,  447 
Glass  soap,  soluble,  327 

for  filling  soft  soaps,  320 
Glue  fat,  92,  93.  94 
Gljcerides,  69,  70 
Glycerine,  69,  157,  486,  487 

cocoanut  oil  soap,  427 

drawing  off",  473 

furnished  by  fats,  359 

Milly's  process  for  production,  1  62 

production  and  great  value  of,  103 

separation  of,  472 

soap,  405 

liquid,  424 
perfumes  for,  441 


INDEX. 


569 


Glycerine — 

soap,  transparent,  428 

Tilghman's  process  for  production 
of,  162 
Glyceryl-oxide,  70 

absorbed  by  acids,  73 
Goa  butter,  124 
Gold  soap,  156 

Gontard's  soap  factory  at  St.  Quen, 
199-202 

Gossage,  on  the  use  of  soluble  glass  in 
soaps,  164 

process  for  silicated  soaps,  327 
Gourd,  oil  of,  98 
Grained  soft  soap,  320 
Grain  or  curd  soaps,  266-284 

soap,  artificial,  320,321 

soaps,  marbling,  201 
Grape-seed  oil,  124 

-stone,  oil  of,  98 
Grate,  204 

Grease  for  toilet  soap,  390,  392 

oil  wngon,  treatment  of  with  sul- 
phuric acid,  .132 
utilization  of  old  wheel,  131 
Greases  for  fine  toilet  soaps,  400 
Great  Britain,  soap  statistics  of,  24 
Greaves  or  crackling  soap,  334 

treating  of,  for  making  soap,  334 
Greenland,  cryolite  of,  6') 
Green  soft  soap,  323,  324 
Grinding  apparatus,  229 

or  fitting  of  soap,  271,  272 
Grodhaus  and  Fink,  investigations  on 
the  extraction  of  tallow  without  of- 
fense, 78 
Ground-nut  oil,  97,  109,  110 
Guppy's  process  for  silicic  soap,  332, 
333 

Guyton  de  Morveau,  46 

Half-boiled  or  Swiss  soap«,  30i)-309 
soaps,  301 

Swiss  soaps,  400,  407 
Half-palm  soap,  formulas  for,  393 
Hand  soap  press,  431 
Hard  soaps,  266-284 

from  potash  lye,  162,  309 
tallow  for  chandlers,  73,  74 
Hazel-nut  oil,  97,  98,  117 
Heating  manufactory  by  steam,  206-  21 1 
of  kettles  by  fire,  213-215 
by  steam,  215-224 
Heintz  on  composition  of  butter,  91 

on  the  composition  of  spermaceti, 
484 

Heliotrope  soap,  411 
Hempseed  oil,  97,  98,  114,  115 
adulteration  of,  141 


Hempseed  oil — 

composition  of,  114 

soft  soaps  from,  319 
Herb  soap,  420 

Hersey's   patent   rotary  soap-pump, 
236-238 
patent  steam  press,  432 
Honey  soap,  405 

perfumes  for,  440 
Hood  for  catching  the  offensive  gases 

from  tallow,  465 
Hops,  Spanish  oil  of,  451 
Horse-chestnut,  oil  of,  98 
fat,  93 

Hubert's  apparatus  for  boiling  soap  by 

surcharged  steam,  219-221 
Hungary,  natron  of,  45 
Hydrate  of  lime,  necessary  to  make 
caustic  alkali,  248 
of  soda,  193 
Hydraulic  press,  475 
Hydrometer  of  Baum^.  167 
Hydrometers  and  thermometers,  555- 

560 

Illipe  oil,  107 
Imperial  measure,  545 

in  apothecaries'%nd  avoirdu- 
pois weights,  value  of,  546 
Implements,  minor,  246,  247 
Impurities  in  fats  and  oils,  262 
Iodine  soap,  419 
Irish-moss  soap,  419 
Iron,  frames  of,  231-233 

kettles,  212,  213 

red,  for  marbling  soaps,  201 

vats,  207,  227 

Jacket  crutching  machine,  245,  246 
Morfit's  steam,  221-224 
St.  John's  steam,  221,  222 

Japan  wax,  485 

Jassamine,  oil  of,  447,  448 

Jonquille  soap,  413 

Juenneman's  process  for  changing  oleic 
into  palmitic  acid,  119-121 

Kalkothar  for  marbling  soaps,  201 
Kalucz,  Hungary  potasli  from  the  salt- 
rocks  in,  2» 
Keton,  480 

Kettles,  204,  207,  211 

cast  and  sheet-iron,  212,  213 
heating  by  steam,  215-224 

of  by  fire,  213-215 
masonry,  21 1 

used  at  Marseilles,  211,  212 
used    in    France,    Belgium,  and 
England,  212 


570 


INDEX. 


King's  foot-power  press,  432 
Kitchen  fat,  94 

Knapp  on  the  efficacy  of  the  globular 
state,  840 

Kocin,  106 

composition  of,  106 

Kraft,  Prof.  T.,  reports  on  sebacic  or 
fatty  acids,  480,  481 

Kurten's  table  of  composition  and  pro- 
duct of  soaps  by  cold  process,  408 

Labor  saving  soap,  385 
Lard,  86-90 

falsification  of,  148 

for  candles,  459 

rendering  of,  by  steam,  Wilson's 
process,  88-90 
Laurel  oil,  97,  123 
Lavender,  oil  of,  448 
Lavoisier,  19 

Leaching  or  washing  of  ashes,  34,  35 
Lead-lined  vats,  227 
Leblanc,  45,  47,  48 

discovery  of  process  for  making 
soda  from  salt,  21 
Lefevre,  method  of  extracting  tallow, 
77 

Leleivre,  19  • 
Lemon,  oil  of,  446 

seeds,  oil  of,  98 

soap,  410 
Length,  measures  of,  547 
Lettuce  soap,  415 
Leubel's  candle  machine,  506,  507 
Liebig's  experiments  on  caustic  potash 
and  soda,  251 

experiments    on    caustic  alkali, 
251 

Light,  artificial,  from  the  flame  of  can- 
dle, principles  of,  460 
Lilly  soap,  415 
Lime,  61-63 

analysis  of,  194 

for  the  removal  of  carbonic  acid 

from  lyes,  248 
hydrated,  61 
impure,  63 
in  fats,  92,  93 
in  preparation  of  lyes,  62 
keeping  of  for  use,  63 
milk  of,  61 
qtialities  of,  61 

quantity  of  hydrate  of,  necessary 

to  make  caustic  alkali,  248 
saponification  by,  472-477 
slacked,  61 
soap,  156 
tests  of,  63 


Lime — 

to  be  applied  in  proportion  to  the 
contents  of  potash  and  soda  to 
pure  carbonate  of  alkali,  tables 
of,  250,  251 
water,  62 
Limette,  oil  of,  448 
Linden  seeds,  oil  of,  98 
Linseed  oil,  97,  98,  117 

adulteration  of,  141 
Lipyloxide,  70 
Liquation,  344 

Liquid  fats  or  oils,  when  they  become 
solid,  69 

glj'cerine  soap,  424 
Liquefaction,  395,  396 

D'Arcet's  views  on,  342 
Litmus,  tincture  of,  177,  178 
Little  pan  soaps,  301 
Liverpool  poor  man's  soap,  335 
London  soap  powder,  387 
Lubricating  soap,  386 
Lye,  Dalton's  table  of  soda  in,  261, 
262 

for  hard  soaps,  266-271 

for  toilet  soaps,  402 

for  treatment  of  bones,  385 

potash  from  wood  ashes,  253,  254 

to  separate  from  soap,  310 

used  at  soap  factory  at  St.  Quen, 

France,  200 
vats,  225,  226 

Marseilles,  227 
Lyes,  Dalton's  table  of  contents,  259, 
260 

for  cold  soaps,  801 
for  elaidin  soft  soaps,  321 
for  olein  soap,  290-292 
for  saponification  of  rosin,  804 
importance  of  maintaining  a  pro- 
per proportion  of  materials  in, 
251 

importance  of  preparation  of,  248 
of  potash,  estimation  of  soda  in, 

185-193 
preparation  of,  248 
preservation  of,  254 
specific  gravity  and  hydrometrio 

test  of,' 258 
testing  the  strength  of,  255 

Mace,  oil  of,  122 

Machinery  and  appliances  for  manipu- 
lation of  soaps,  428 
iMacquer,  46 
Magnesia  soap,  156 
Malabar  tallow,  124 
Malherbe,  40 


INDEX. 


571 


Manipulation  of  soap,  428-442 
Manufactory  of  soap,  heated  by  steam, 
206-211 

Marbled  or  Marseilles  soap,  266 
Marbling,  D'Arcet's  views  on,  343-346 

imperfect,  273 

of  grain  soaps,  201 

of  soap,  272 

soap,  sub-lye  used  in,  273 
Margaric,  71 
Margarine,  71 

Margarinic  acid,  melting  and  boiling 

points  of,  481 
Marine  soap,  388 
Marjoram,  oil  of,  451 
Marseilles,  establi-liment  of  sonp  in- 
dustry in,  20 
fabrication  of  artificial  soda  at,  48 
kettles  used  at,  211,  212 
lye  vats,  227 
soap,  266,  274-276 

factory  at  St.  Qnen,  199-202 
soap,  formulas  for,  273,  274 

from  cotton-seed  oil,  296-298 
statistics  of,  24 
Marsh-mallow  soap,  405 
Masonry,  frames  of,  280,  231 
kettles,  211 
vats,  205 

Materials  for  candles  and  their  prepa- 
ration, 463-487 
used  in  the  manufacture  of  sonp, 
26-129 

Maujot,  researches  of,  on  fatty  bodies, 
458 

Measures,  American,  549 

British  imperial,  549 

of  capacity,  548 

of  length,  547 

superficial,  548 
Mechanical  aid  in  making  cold  soaps, 
302 

stirrer,  302 
Medicated  soaps,  409-419 

soft  soap,  388 

tar  soap,  418 
Melsen's  process  of  saponification,  480 
Melting  and  freezing  and  boiling  points 

of  ditferent  substances,  560 
Mercurial  soap,  419 
Mercury  soap,  156 
Metherie,  de  la,  46 

Metric  system.  Congressional  report 

on,  543,  544 
Metric  system  of  weights  and  measures, 

543-554 
Mill,  Bogardus's  eccentric,  229 
centrifugal,  for  tallow,  470 
for  grinding  alkalies,  229 


Millefleur  soap,  413 
Mills,  soap,  435 

Milly's  process  for  production  of  gly- 
cerine, 162 
Miscellaneous  useful  soaps,  383-388 
Mixed  barilla,  44 

Mohr,  base  of,  for  alkalimetry,  179 
Molasse.y,  potash  from,  38,  39 
Montigny,  46 

Morfit's  steam  jacket,  221-224 
Morgan's  moulding  machine,  508-512 
Morrhua  oil,  96 

Mottled  castile  soap  from  cotton-seed 

oil,  298 
Moulded  candles,  501-527 
Moulding  candles  by  hand,  503,  504 

by  steam,  French  apparatus 
for,  520-522 

by  machinery,  504-527 

machine,  Ashley's,  513 

of  candles,  when  first  made,  458 

paraffine  candles,  522 

spermacetic  candles,  523,  524 

stearic  acid  candles,  517,518 
by  hand,  518-520 

wax  candles,  525 

wheel.  Camp's,  513-^515 
Moulds  for  candles,  501,  502 

for  candles,  improved,  535,  536 

for  stearic-acid  candles,  518 
Mouries,  process  of,  339-341 
Mousseleine  soap,  415 
Muddiness,  cause  of,  in  soft  soaps,  318 

in  soft  soaps,  321 
Muriatic  acid  for  dissolving  bones,  335 
Musk  or  Bisam,  453 

tincture  of,  455 

Windsor  soap,  417 
Muspratt,  manufacture  of  artificial  soda 

by,  21 
Mustard-seed  oil,  116 

white,  oil  of,  98 
Mutton  tallow  for  candles,  458 
Myrtle  wax,  126,  485 

Naples  soap  or  shaving  cream,  426 
Narbonne,  soda  of,  42 
Natron,  41,  42,  44,  45 
Neat's-foot  oil,  94 

adulteration  of  142 
Needle  for  threading,  501,  503 
Neroli  or  orange-flower  oil,  449 
Neutral    fats,    decomposition    of,  by 

super-heated  steam,  162 
New  soaps  by  new  methods,  337-350 
Night  lights  or  tapers,  542 
Nitric  acid,  action  of,  on  oils,  74 

normal,  quantities  that  will  neu- 
tralize bases,  182 


572 


INDEX. 


Nitric  acid — 

required  for  mixed  alk;»lie9,189,190 
Normal  acid  liquor,  865-369 

alkali,  184,-185 

alkaline  liquor,  865,  369.  370 

nitric  acid,  quantities  which  will 
neutralize  bases,  182 
Nutmeg,  analysis  of,  122 

butter  of,  122 
Nutmegs,  oil  of,  452 
Nut  oil,  97,  98,  115 
Nymph  floating  soap,  421 

Oatmeal  soap,  419 
Ocuba  wax,  126,  485 
Offal  fats,  yield  of,  by  means  of  sul- 
phuret  of  carbon,  131,  132 

recovery  of,  130-139 
Offenbach's  palm  soap,  H83 
Oil,  almond,  97,  98,  109 

avocado, 111 

beechnut,  97,  115,  1 16 

ben,  97,  110 

camelina,  97,  98,  116 

carapa,  1  24 

caraway  seed,  447 

cassia,  452 

castor,  97,  98,  113 

cocoanut,  105-1U7 

coleseed,  97,  98,  109 

colza,  116 

cotton-seed,  97,  98,  111-113,  296- 
300 

for  Marseilles  soaps,  275 
gallipoli,  107,  108 
geranium,  447 
grape-seed,  124 
ground-nut,  97,  109,  110 
hazel-nut,  97,  98,  117 
hemp-seed,  97,  98,  114,  1  15 
linseed,  97,  98,  117 
morrhua,  96 
mustard-seed,  116 
neat's-foot,  94 
nut,  97,  98,  115 
of  belladonna  seed,  124 
uf  bergamot,  443.  444 
of  bitter  almonds,  444-416 
of  Canada  snakeroot,  452 
of  cinnamon,  452 
of  cloves,  448 
of  fennel,  446 

of  gaultheria  or  wintergreen  o"l, 

446,447 
of  jassamine,  447,  448 
of  laurel,  97,  123 
of  lavender,  448 
of  lemon,  446 
of  limette,  448 


Oil— 

of  mace,  122 
of  marjoram,  451 
of  nutmegs,  452 
of  patchouly,  419 
of  pimento,  452 
of  Portugal,  449 
of  rosemary,  452 
of  roses,  449-451 
of  sassafras,  451 

of  sweet  almonds,  adulteration  of, 
140 

of  thyme,  451 
of  tobacco  seeds,  124 
of  valerian,  443 
of  vitivert,  452 
olive,  98,  99 

or  fat,  none  used   alone,  which 

makes  the  faultless  soap,  2(j2 
palm,  99-104 
palm  kernel,  104 
poppy  seed,  97,  98,  113,  114 
raja,  96 

rapeseed,  97,  98,  109 

sesame,  108,  109 

sunflower,  97,  111 
Oils  and  fats,  68-124 

advantage  in  mixing,  262,  263 
decomposition  of,  68 
impurities  in,  262 
of  vegetable  origin,  97-124 
used  in  the  manufacture  of 
soaps,  69 

assays  of,  148-147 

coloration  of,  143,  144 

coloration  of,  taken  by  different, 
146,  147 

fish,  95 

fixed,  98 

or  liquid  fats,  when  tliey  become 

solid,  69 
physical  properties  of,  98 
sebacic  acid,  from  sediment  of,  131 
train,  95 
volatile,  443-455 

volatile,  specific  gravities  of,  442- 
453 

yielded  by  vegetables,  quantities 
of,  97,  98 
Old  brown  Windsor  soap,  406 
Oleabutyric  acid,  91 
Oleic  acid,  117-121 

adulteration  of,  142 

characteristics  of,  118 

glyceryl  oxide,  71 

in  the  fabrication  of  soap,  119 

recovery  of,  480 

reduced  by  Chevreul,  458 

soap,  288-296 


INDEX. 


573 


Oleic  acid — 

with  hydrate  of  potash,  dissolved 
into  palmitic  and  acetic  acids, 
119 

Olein,  117-121 

acid,  in  vegetable  oils,  71 
constitution  of,  157 
or  stearic  glycei'yl  oxide,  70 
quantity  obtained  from  oleic  acid, 
295 

soap,  288-296 
what  it  is,  70 

Oleines,  70 

Oleophane,  424 

Olive  oil,  97-99 

adulteration  of,  140 
discoloration  of,  by  heat,  143 
soaps  will  bear  no  salt,  325 
white  soap,  from  composition  of, 
280 

Onoporde  acanthe,  oil  of,  98 
Orange-flower  oil,  449 
Orange  soap,  411 
Orleans,  Duke  of,  47 
Ox-gall  soaps,  for  scouring  woollens, 
384 

Palmitic  acid  from  palm  oil,  melting 

and  boiling  points,  480,  481 
Palmitic  acid  or  margaric  acid,  71 
Palmitin,  70,  157 
Pnlmitin  or  margarine,  71 
Palm-kernel  oil,  104 
Palm  oil,  24,  99-104 

adulteration  of,  142 

bleaching  of,  101 

color  of,  in  soap,  101 

composition  of,  101 

consumption  of,  100 

consumption  of,  in  England,  100 

extraction  of,  100 

for  candles,  459 

free  acids  in,  101 

melting  points  of,  101 

soap,  hardness  and  brittleness  of, 
to  correct,  284 

soaps,  salt  which  they  will  bear, 
325 

the  peculiar  acid  of,  70 
Palm-tree  wax,  125 
Palm  soap,  284,  285 

Dresden,  383 

half,  393 

for  stock,  397 

formulae  for,  285 

Offenbach's,  383 

Swiss,  306,  307 
Paraffine,  addition  of  stearic  acid  to, 
483 


Paraffine — 

addition  to  stearic  acid,  for  can- 
dles, 458 
bleaching  of,  483 
candles,  522 

moulding,  522 
discovery  of,  458 
melting  points  of,  483-522 
production  and  uses  of,  482,  483 
scale,  482 
soap,  419 

Paris,  manufacture  of  candles  at,  457 
Taste  for  Marseilles  soap,  266 
Paste,  homogeneity  of,  295 
Pasting,  276,  394 
Patchouly,  oil  of,  449 
Patent  candles,  582-536 
Payen,  47 

Pearl  soap  powder,  387 
Pela  wax,  485 

Pelouze,  method  of  saponification  by 

sulphuretted  alkalies,  338 
Pentadecyl  acid,  melting  and  - boiling 

points  of,  481 
Perfume  for  Cashmere  soap,  442 
Perfumes  for  elder  flower  soap,  442 
for  glycerine  soaps,  441 
for  honey  soap,  440 
for  rose  soap,  441,  442 
for  toilet  soaps,  403-427 
for  white  Windsor  soap,  441 
Perfuming  soaps,  materials  for,  443- 
455 

steam  for  finishing  soap  cakes,  438 
toilet  soaps,  440-442 
Permanganate  of  potash,  for  whitening 

tallow,  470 
Perutz's  fine  soda-grain  soap,  320 

improvement  of   Mege  Mouries' 
process,  341 
Perutz,  on  the  success  of  Mege  Mou- 
ries, 341 

1  Perutz's  table  of  anhydrous  potash,  259 
of  anhydrous  soda,  2b 1 
Peruvian  balsam,  454 
Petroleum  soap,  419 
Pimento,  oil  of,  452 
Pine-tree  oil,  97 

Pipes  to  draw  off  lyes  from  kettles,  207 

Pipette,  the,  172-174 

Pitch,  falsification  of,  wax  with,  150 

Pitch  tree  oil,  97 

Plant  of  a  soap  factory,  197-247 

Plants,  combustion  of  in  furnaces,  for 

potash,  33,  34 
Plaster  of  Paris,  detection  of,  in  lard, 

148 

Plotting  machines,  436-438 
hydraulic,  437,  4ii8 


574 


INDEX. 


Plum  seeds,  oil  of,  98 
Polishing  and  finishing  of  candles,  528- 
631 

soap  cakes,  488,  480 
machines  for  candles,  529-581 
Poncein  soap,  884 
Poole  &  Hunt's  iron  frames,  282 
Poor  man's  soap,  385 
Poppy  oil,  adulteration  of,  141 
seed  oil,  97,  98,  113,  114 
Portugal,  oil  of,  449 
Potash,  26,  27-41 

a   small   quantity   in  vegetables 
which  grow  on  the  sea-shore,  28 
and  soda,  determination  of  rela- 
tive quantities  of,  in  soaps, 
855 

mixtures  of,  in  soaps,  376-879 
proportions  of,  for  soft  soaps, 
316,  817 
anhydrous,  259 
carbonate  of,  89,  41 

to  change  into  caustic  alkali, 
249 

caustic,  Liebig's  experiments,  251 
contents  of  lyes,  Dalton's  table  of, 

259,  260 
extraction  of,  82-41 
fictitious,  36 

from  beet-root  molasses,  88,  89 
from  the  salt  rocks  in  Kalucz, 

Hungary,  28 
from  the  salt  rocks  in  Strassfort, 

Prussia,  28 
from  vegetables  which  grow  inland, 

29 

in  carbonate  of  potash,  191,  192 
in  different  vegetables,  table  of,  30 
in  hydrate  potash,  191,  192 
in  the  younger  parts  of  plants,  29 
in  vegetables,  28 

lye  from  wood  ashes,  preparing, 

253,  254 
lye,  hard  soap  from,  162,  309 
lyes,  estimation  of  soda  in,  185-198 
manufacture  of,  in  Russia  and  the 

United  States,  28 
purification  of,  40,  41 
red  American,  35-37 
soap  to  transform  into  soda  soap 

by  the  use  of  salt,  310 
soft  toilet  soaps  of,  424 
sources  of,  28 

table  of  lime  to  be  applied  in  pro- 
portion to  contents  of  pure  car- 
bonate, 250 
Potashes,  table  of  the  composition  of 
the  principal  commercial,  39,  40 
the  most  esteemed,  39 


Potassium,  26 

Powder  soap,  887 

Powdered  soap,  421 

Preservation  of  lyes,  254 

Press,  hand,  for  soap,  431 

Hersey's  patent  steam  soap,  482 
soap,  King's  foot-power,  432 

Presses,  elbow,  467-469 

for  extracting  fats  from  greases, 
466-469 

Price  &  Co.,  London  candle  factory  of, 
460 

Process  of  Mege  Mouries,  389-341 
Proctor  on  production  of  wintergreen 
oil,  446 

Properties,  physical,  of  oils,  88 
Proportions  of  fats  and  lyes,  263-266 
Purification  of  potash,  40,  41 
Purifying  and  whitening  tallow,  470 

the  grease  for  toilet  soap,  890-392 
Putrid  waters,  utilization  of,  180 

Qualitative  assays  of  oils,  144-147 
Quartz  soap,  384 

Radish-seed,  oil  of,  98 

Rags,  fatty,  treatment  by  sulphuret  of 

carbon,  132 
Raja  oil,  96 
Ralston's  cutter,  243 
Ram  to  mould  soap,  207 
Rapeseed  oil,  97,  98,  109 

adulteration  of,  141 

residue,  utilization  of,  131 
Reaumur,  thermometer,  551,  557-560 
Recovery  of  offal  fats,  180-139 

of  refuse  fats  and  greases,  130-189 
Red  American  potash,  85-87 

oil,  commercial,  117-121 
Refuse  fats  and  greases,  recovery  of, 
180-189 

Refined  carbonate  of  soda,  54-55 
Relargage,  277 

Remelter,  Whittaker's,  881,882 
Remelting  of  soap,  880-382 
Rendering  and  purifying  the  grease  for 
toilet  soaps,  890-392 
lard  by  steam,  88-90 
tallow,  without  offence,  Vohl's  pro- 
cess, 84-86 
Residues  of  rapeseed  oil,  utilization, 
181 

Residuum  of  distilled  fat,  181 
Resinous  grain  soap,  287,  288 
Resins,  falsification  of  wax  with,  150 
Rose  floating  soap,  421 

leaf  soap,  415 

shaving  cream,  426 

soap,  403,  404 


INDEX. 


575 


Rose  soap — 

perfumes  for,  441,  442 
Windsor  soap,  416 
Rosemary,  oil  of,  452 
Roses,  attar  of,  449-451 

oil  of,  449-451 
Rosin,  abietic  acids  in,  128 
action  of  train  oil  on,  96 
and  fat,  saponification  of,  304 
for  filling  soft  soaps,  319 
for  removal  of  touch  from  sub-lye, 
283 

in  elaidin  soaps,  322 

in  soap,  285 

in  soap-making,  129 

in  soaps,  determination  of,  357 

makes  soaps  soft  and  pasty,  304 

or  colophony,  126-129 

percentage  applied  to  fats,  304 

saponification  of,  304 

Sutherland's  method  for  testing  in 

soap,  360 
Swiss  soap,  368 

the  acids  in  affinities  for  alkalies,!  64 

uses  of,  129 

uses  of,  in  soaps,  164 
Rosin  soap,  129,  285-289 

Altenburge's,  383 

by  cold  process,  304 

formula  for,  286 

separation  from  salt,  283 

transparent,  305 
Rosin  soaps,  common,  filled,  326 

English,  286-287 

large  number  of,  304 
Rosins,  preparation  of,  in  the  United 

States,  285 
Rubinium,  60 
Rubidium,  oxides  of,  156 
Rutschman's  hydraulic  soap  plotter, 
437,  438 

power  soap-mill,  435 

rotary  soap-plotter,  430,437 

stripping  machine,  434,  485 

Saint  John's  steam  jacket,  221,  222 

Quen,   France,   soap   factory  at, 
199-202 

Salicor,  42 

Salicornia  annua,  42 
Europoea,  42 

Salicylic  soap,  419 

Salin,  32 

Salmo-phymallus,  fat  of,  96 
Salsola  soda,  42,  43 
Salt,  67,  68 

a  solution  of,  filling  soft  soaps, 
319 

action  of,  on  lye,  268 


Salt— 

and  sulphate  of  copper,  dissolved 

by  the  fats,  74 
the  use  of,  in  making  soap,  310, 

311 

Salted  barilla,  44 

soda,  artificial,  52-54 
Salting  out,  310 

Salts,  efi^ect  of,  in  separating  soap  from 
its  lyes,  161 
in  vegetables,  28 
of  soda,  caustic,  57,  59 
soluble  and  insoluble,  in  diflFerent 

plants,  31 
soluble,  composition  of,  from  cer- 
tain vegetables,  31,  32 
Sfind  soap,  334 
Saponification,  156-165 
by  lime,  472-477 

by  lime,  water,  and  pressure,  472 
by  sulphuric  acid  and  distillation, 

472,  478,  479 
by  water   and   distillation,  472, 

479,  480 

by  water  under   high  pressure, 

472,  480,  481 
D'Arcefs  practice,  341 

views  on,  342 
eflFect  of,  on  fats,  156 
of  fats  by  means  of  carbonated 

alkalies,  337,  338 
of  fiits  by  sulphuretted  alkalies, 

338 

of  lime,  De  Milly's  process, 477, 478 

of  rosin,  304 

of  rosin  and  fat,  304 

theory  of,  17 

to  test,  473 
Sapophane,  424 
Sassafras,  oil  of,  451 
Savon  a  la  marechale,  414 

a  la  violette  de  Parme,  414 

de  muguet,  415 

hygienique,  414 
Savonettes,  427 

Sawdust  for  filtering  oil,  treatment  of, 
131,  132 

Scales  and  weights  in  alkalimetry,  177 
Scheele,  19 
Scouring  balls,  384 

soap,  French,  385 

tablets,  385 
Sea-weeds,  soda  from,  43 
Seal  oil,  95 

Sebacic  acid  in  soap,  Buckner's  method 

to  determine,  359 
Sebacic  acids,  congealing  points  of,  3.')8 
in  soaps,  determination  of,  357, 
359 


676 


INDEX. 


Sebacic  or  f:itty  acids,  Kraft's  report 

on,  480,  481 
Sebacylic  acid,  486 

high  fusion  point  of,  486 
Separation,  277,  394 
Sesame  oil,  108,  109 

adulteration  of,  1 41 
soda  soap  from,  109 
uses  of,  109 
Sesamum  oil,  97,  98 
Shaker  soft  soap,  386 
Sharks'  livers,  oil  of,  96 
Shaving  compounds,  421 
cream,  almoml,  426 
ambrosial,  426 
by  boiling,  426 
or  Naples  soap,  426 
rose,  426 
creams,  424 
soaps  in  tablets,  420 
Shea  butter,  104,  121 
Sheet-iron  vats,  207 
Sieve,  drum,  229,  230 
Silica,  preparation  of,  for  soaps,  332 
Silicated  and  other  filled  soaps,  325- 
336 

Silicated  soaps,  327 
Silicic  soap,  331,  332 

Guppy's  process  for,  332,  333 
Silver  soap.  156 
Siphon,  228 

Slabber,  the  champion,  242,  243 
Slabbing  and  barring   machine,  Van 

Haagen,  239 
Smell  of  melting  tallow,  correcting  of, 

80 

Snakeroot,  oil  of,  452 
Soap,  156 

a  test  of  civilization,  17 

almond-grain,  296 

analysis,  351-379 

and  alkali  trades,  history  of,  19-25 

balls.  427 

bleaching,  296 

boiling  by  surcharged  steam,  219, 
220 

in  France,  200,  201 
bone,  334,  335 
borax,  305 

caking  making  machine,  428-430 

castile,  274-276 

formulas  for,  273,  274 

from  cotton  seed  oil,  296-300 

cocoanut-oil,  by  cold  process,  303 

consistency    of,    effected    by  the 
melting  points  of  the  fats,  163 

crown,  second  quality,  323 

crutching  machine,  243-246 

curd,  281-284 


Soap — 

decomposition  of,  473 
determination  of,  as  to  admixtures, 

362 

elaidin,  288-296 

English  crown,  first  quality,  323 

essences,  422 

factories,  French,  199-208 
factory  at  St.  Quen,  199-202 

building  for,  198 

establishment  of,  197-247 

location  of,  197 

plant  of,  197-247 
fig,  320 
fitted,  201 

frame,  Whittaker,  232,  238 
frames,  230-236 
gold,  156 

grain,  artificial,  320,  321 
grained  soft,  320 
Greaves  or  crackling,  334 
green  soft,  323,  324 
grinding  or  filling,  271,  272 
Guppy's  process  for  silicic,  332, 
333 

bard,  from  potash  lye,  309 
industry,  establishment  of,  in  Mar- 
seilles, 20 
insoluble  in  strong  lyes,  161 
lime,  156 

Liverpool  poormau's,  335 
magnesia,  156 

manufacture,   importance  of  the 
art,  17 

in  England,  21,  22 

in  Germany,  22 
marbled  or  Marseilles,  266 
marbling  of,  272 

Marseilles,  formulas  for,  273,  274 
materials  used  in  manufacture  of, 

26-129 
mercury,  156 
mills,  435 
olein,  288-296 

olive  oil,  composition  of,  280 
palm,  284,  285 
poncein,  334 

press,  Mersey's  patent,  432 
pump,  Hersey's  rotary,  236-238 
purest  in  commerce,  275 
quartz,  334 
remelting  of,  380-382 
resinous  grain,  287,  288 
rosin,  285-287 

by  cold  process,  304 
sand,  334 
silver,  156 
slabber,  242,  243 
soft,  elaidin,  321,322 


INDEX. 


577 


Soap — 

soluble  glass,  327 

statistics  of  various  countries,  24 

stripping  of,  434 

substitutes  for,  25 

Swiss  olein,  308 

palm,  306,  307 

rosin,  308 

white  wax,  307 

yellow,  307 
tallow,  281-284 

by  cold  process,  303 

curd  (grained),  309-313 
tin,  166 

transparent  rosin,  305 
turpentine,  287,  288 
wax,  296 

what  it  is,  17,  156 
when  first  made,  20 
yellow,  285-287 
zinc,  156 
Soaps,  acid  salts,  196 

action  of  in  washing,  195 

and  candles,  manufacture  of  true 

chemical  industries,  18 
and  glycerine  furnished  by  fats, 

Buchner's  table  of,  359 
application  of,  195,  196 
by  boiling,  248-256 
by  cold  process,  composition  and 

product  of,  408 
by  steam  pressure,  346-350 
chemical  equivalents  applicable  to, 

152-155 
cold,  302 

common  cocoanut  oil,  326 
common  filled  rosin,  326 
curd  or  grain,  266-284 
elain,  from  oleic  acid,  119 
extempore,  301,  400 
fabrication  of,  248-336 
for  dyeing,  195 

for  wool-washing  and  fulling,  195 
hard,  266-284 

from  potash  lye,  162 
importance  of  making  good,  honest, 
18 

made  with  potash  and  soda,  26 
manipulation  of,  428-442 
manufacture  of,  in  United  States, 

18,  23 
marbling  grain,  201 
not  entirely  soluble  in  cold  water, 

164 

of  oleic  acid  and  rosin,  sapouime- 

try  of,  375,  376 
of  solid  and  liquid  fatty  acid,  sa- 

ponimetry  of,  370-375 
of  weak  stock,  163 

37 


Soaps — 

silicated,  327 

silicated  and  other  filled,  325-336 
soda,  266-284 
soft,  314-324 

soft,  cause  of  thickness  in,  318 
soft  with  soda,  Gentele's  formula 

for,  315,  316 
solid,  266-284 
soluble  glass  in,  164 
Swiss  or  half-boiled,  306-309 
table  of  analyses,  363 
toilet,  195,  389-427 
useful,  383-388 
valuation  of,  364,  365 
white  soft,  322 

with  potash,  always  soft,  and  re- 
tain their  glycerine,  161 
Soda,  26,  41-60 

and  potash,  proportions  of,  for  soft 
soaps,  316,  317 
determination  of  relative  quan- 
tities of,  in  soaps,  355 
anhydrous,  table  of  specific  gravity 

and  hydrometric  degree,  261 
artificial,  41 

expense  of  manufacturing  in 

France,  52 
history  of  the  fabrication  of, 

45-48 
salted,  52-54 
ash,  by  the  ammoniacal  process, 
561 

calcination  of,  50 
carbonate  of,  for  filling  soft  soaps, 
319 

for  rosin  soaps,  304 
to  change  into  caustic  soda, 
250 

carbonates  of,  42 

caustic,  from  cryolite,  60 

caustic  lyes  of,  248 

caustic  salts  of,  57-59 

chemically  pure,  composition  of,  42 

crystals  of,  55-57 

English  caustic,  analysis  of,  58 

fabrication  of  artificial  at  Mar- 
seilles, 48 

fabrication  of  crude,  48 

from  salt,  discovered  by  Leblanc, 
21 

from  sea-weeds,  43 
grain  soap,  Perutz's,  320 
hydrate  of,  table  of,  193 
in  lye,  Dalton's  table  of,  261,  262 
•    in  lyes  of  potash,  estimation  of, 
i:  185-193 

in  vegetables  which  grow  on  the 
seashore,  29 


678 


INDEX. 


Soda — 

manufacture  of  artificial,  by  Mus- 

pratt,  21 
of  Aigues-Mortes,  43 
of  Alicante,  43 
of  Carthagena,  43 
of  Malaga,  43 
of  Narbonne,  42 
refined  carbonate  of,  54 
salsola,  42,  43 

Boap,  made  with  bone  fat,  92 
soaps,  266-284 
sulphate  of,  48-52 
table  of,  193 

table  of  anhydrous  of,  193 
table  of  crystallized  carbonate  of, 
193 

table  of  lime  to  be  applied  in  pro- 
portion to  contents  of  pure  car- 
bonate, 251 
Sodas,  natural,  42 

Spanish,  43,  44 
Sodium,  26 

Soft  soap,  a  good  appearance  of,  314 
Belgian,  388 
boiling  of,  317,  318 
borax,  386 

cause  of  dulness  of,  314 

domestic,  386 

elaidin,  321,  322 

grained,  320 

green,  323,  324 

Shaker,  386 
Soft  soaps,  314-324 

cause  of  thickening  in,  318 

filling,  319 

from  oleic  acid,  119 

judging  of  in  making,  318 

to  give  a  greenish  color  to,  319 

use  of  caustic  soda  in,  315 

what  they  are,  314 

white,  322 
Soft  toilet  soap,  white,  424,  425 
Soft  toilet  soaps  of  potash,  424 
Solid  fats,  when  they  become  liquid, 
69 

soaps,  266-284 
Soluble   glass  for  filling   soft  soaps, 
320 
in  soap,  164 
soap,  317 

Solvay,  Ernst,  process  for  soda  ash, 
561 

Sophistication  of  soaps,  materials  used 
for,  325 

Soutfrice  &  Co.,  offal  utilized  by,  130 
South  America,  natron  of,  45 
Spanish  sodas,  43,  44 
Sperm  candles,  Belmont,  532 


Spermaceti,  483,  484 
candles,  458,  523 
machine  for  cutting,  484 
soap,  420 

tendency  to  crystallize,  484 
what  composed  of,  484 
Star  candles,  532 

Starch,  falsification  of  wax  with,  151 

for  filling  soft  soaps,  319 
Statistics  of  soaps  of  various  countries, 
24 

Steam,  advantage  of  the  system,  207 
decomposition  of  neutral  fats  by, 
162 

heating  of  kettles  by,  215-224 
jacket,  Morfit's,  221-224 
St.  John's,  221,222 
manufactory  of  soap  heated  by, 
206-211 

perfuming  for  finishing  soap  cakes, 
438 

press,  Hersey's  patent,  432 
pressure   in   pounds    and  atmo- 
spheres, 560 
pressure,  soaps  by,  346-350 
series,  216-218 
Stearic  acid,  addition  to  paraffine,  483 
and  stearine,  the  base  of  most  cau- 
dles, 454 
bleaching,  518 
candles,  moulding,  517,  518 
crystallization  of,  to  remedy,  517 
for  candles,  471 
Stearic  acid  industry,  great  importance 
of,  459,  460 
preparation  of,  471 
Stearic  glyceryl,  oxide,  or  oleine,  70 
Stearine  and  stearic  acid  the  base  for 
most  candles,  459 
candles,  515-517 
constitution  of,  157 
manufacture  of,  by  De  Milly,  459 
what  it  is,  70 
Stearines,  70 

Stein,  charcoal  coves  for  disinfecting,  80 
investigations  of  on  the  extracting 

of  tallow,  without  offence,  78 
on  disinfecting  the  odorous  pro- 
ducts in  rendering,  78-81 
Stirrer,  mechanical,  302 
Stirring  olein  soap  in  the  frames,  294- 
296 

Stockhardt's  table  of  the  congealing 

points  of  sebacic  fields,  358 
Stock  soap,  palm,  397 
Store-rooms,  205 

Stoves,  use  of,  in  drying-rooms,  209 
Strassfurt,  Prussia,  potash  from  the 
salt  rocks  of,  28 


INDEX. 


579 


strength  of  lyes,  testing,  255 
Stripping  machines,  Rutschman's,  434, 
435 
of  soap,  434 
Strunz's  soap  crutching  machine,  243, 
244 

Sub-lye,  touch  of,  to  remove,  283 
Suinter,  manufacture  of,  133 
Sulphate  of  soda,  48-52 
Sulphur,  falsification  of  yellow  wax 
,    by, 150 
Sulphur  soap,  418 

Sulphuric  acid,  saponification  of  fats 

by,  478,  479 
Sulphuret  of  carbon,  to  dissolve  fats, 
132 

treatment   of  ofi'al  fats  by, 
131,  132 
Sulphuretted  alkalies,  338 
Sunflower-seed  oil,  97,  111 

oil  of,  98 
Superficial  measures,  548 
Superfine  soaps,  412 
Superheated  steam,  use  of,  for  heating, 
216,  217 

Surcharged  steam,  boiling  soap  by, 
219-221 

Sutherland's  method  for  testing  the 

rosin  in  soap,  360 
Swiss  olein  soap,  308 

or  half-boiled  soaps,  306-309 

palm  soap,  306,  307 

rosin  soap,  308-310 

soap,  308 

white  wax  soap,  307 
yellow  soap,  307 
Symbols  proposed  for  weights,  551 

Table  of  the  quantities  of  ashes  and 

potash  in  different  vegetables,  30 
Tablets,  scouring,  385 

shaving  soaps,  420 
Tallow  bleaching,  470,  471 

candles,  early  manufacture  of,  457 

how  first  made,  458 
centrifugal  mill  for,  470 
curd  soap,  309-313 
hood  for  catching  the  ofi^ensive  gas 

from,  465 
machines  for  cutting,  463,  464 
Malabar,  124 
of  virola,  123 

preparation  of,  for  candles,  463 
Price's  process  for  melting,  86 
rendering,  463 

by  open  fire,  463 

by  steam,  463 
saponification  of,  by  De  Milly's 
process,  477,  478 


Tallow- 
soap,  281-284 

by  cold  process,  303 
soaps,  will  bear  no  salt,  325 
to  extract,  75-76 

to  obtain  hai-d,  for  chandlers,  73, 
74 

vegetable,  121 

Vohl's  process  for  removing,  with- 
out oflFence,  84-86 

wax  adulterated  with,  151 
Tallows,  75-86 

falsifications  of,  149 

melting  and  refining,  by  steam,  505 

vegetable,  485 
Tannin  soap,  419 
Tapers,  540-542 
Tar  soap,  medicated,  418 
Tartar,  ashes  from,  37 
Taulet,  apparatus   of,  for  extracting 

tallow,  77 
Temperature  of  dryiqg-room,  208 
Thermometers,  551,  555,  557-560 
Thickness  in  soft  soap,  cause  of,  318 
Thyme,  oil  of,  451 
Thymol  soap,  419 

Tilghman's  apparatus  for  decomposition 
of  neutral  fats,  162 
process  of  saponification,  480 
Tin  soap,  156 

Tincture  of  ambergris,  455 
of  civet,  454 
of  cochineal,  177-179 
of  litmus,  177,  178 
of  musk,  455 
Tobacco  seeds,  oil  of,  124 
Toilet  soaps,  195,  389-427 
by  boiling,  392-399 
by  the  cold  process,  400-408 
coloring,  439 

made  by  cold  process,  392 

names  of  French,  417 

perfuming,  440-442 
Tooth  soap,  418 
Torsk  livers,  oil  of,  96 
Touch  of  sub-lye,  to  remove,  283 

soaps  adjusted  upon  a,  326 
Toy  candles,  538 
Train  oils,  95 

for  soap,  95 

purifying,  95 
Transparent  glycerine  soap,  423 

soap  by  the  cold  process,  422-125 

simple  method  for  cheaper, 
423 

old  method,  423 
soft  soaps,  424 
rosin  soaps,  305 
toilet  soap,  422-424 


580 


INDEX. 


Trays  of  tin  plate,  474 
Tripoli,  natron  of,  45 
Troy  weight,  550 

Tiianermann's  table  of  anhydrous  pot 
ash,  259 
soda,  261 
Turnip-seed,  oil  of,  98 
Turpentine,  128 

investigations  of  Laurent,  128 
of  Maly  on,  128 
of  Unverdorben  on,  128 
soap,  287,  288,  419 

United  States,  manufacture  of  soap  in, 
18,  22 
soap  statistics  of,  24 
Useful  soaps,  miscellaneous,  383-388 

Valerian,  oil  of,  443 
Valuation  of  soaps,  364,  365 
Van  Haagan's  slabbing  and  barring  ma- 
chine, 239 
Vanilla  soap,  416 

Varnish  for  decorated  candles,  539 
Vat,  lead  lined,  227 
Vats,  iron,  227 

large  masonry,  205 
lye,  225,  226 
sheet  iron,  207 
Vegetable  fatty  bodies   employed  in 
making  soap,  97 
oils  and  fats,  97-124 
for  candles,  459 
oleine  acid  in,  71 
refuse,  purification  of,  130 
tallow,  121 

waxes  and  tallow,  485 
Vegetables,  potash  in,  28 

quantities  of  oils  yielded  by,  97, 

98 

salts  in,  28 

table  of  potash  and  ashes  in,  30 
Venice,   manufacture   of  candles  at, 
457 

Ventilation  in  drying-room,  209 
Vesiculos  habens,  43 
Violet  soap,  416 

Windsor  soap,  417 
Virola,  tallow  of,  123 
Vitibert,  oil  of,  452 
Vohl's  apparatus  for  removing  tallow, 
463 

Vohl's  process  for  rendering  tallow 

without  otfense,  84-86 
Volatile  oils,  adulteration  in,  443 

and  other  materials  tor  per- 
fuming soaps,  443-455 
testing,  443-455 
Volumetric  analysis,  167,  1G8 


Washing,  action  of  soaps  in,  195 
Warm  air,  drying-room  with,  208-211 
Water,  64-67 

absorbed  by  soaps,  325 

and  distillation,  saponification  of 

fats  by.  479,  480 
Fleck  test  of,  64-67 
for  a  soap  factory,  199,  202 
importance  of,  in  a  factory,  207 
in  manufacture  of  soap,  64 
proportion  of,  absorbed  by  soaps, 
325 

to  make  caustic  potash  and 
soda,  251,  252 
Waters,  soap-maker's,  310 
Watson's   process  for   purifying  and 

whitening  tallow,  470 
Watts'  method  for  bleaching  tallow,  470 
Wax  candles,  524 

artificial,  532,  533 
Belmont,  532 
how  first  made,  458 
Carnauba,  126,  485 
Chinese,  485 
Japan,  485 
myrtle,  126,  485 
ocuba,  126,  485 
of  bicuyda,  126 
or  bleaching  soap,  384 
palm  tree,  125 
pela,  485 
soap,  296,  419 

Swiss  white,  307 
tapers,  540 

machine   for    making,  540, 
542 

white,  125 
yellow,  125 
Waxes,  125,  126,  484,  485 
falsification  of,  150,  151 
vegetable,  485 
Weights  and  measures,  543-554 

relative    value   in  distilled 
water,  546 
French,  549 
Whale  oil,  95 

soap,  387 
Wheel,  Edinburgh,  498,  499 
White  Castile  soap,  281 

Marseilles  soap,  274-276 
soap,  by  the  cold  process,  402,  403 
from  cocoanut  oil,  398,  399 
from   olive   oil,  composition 
of,  280 
soft  soap,  424,  425 

soaps,  322 
Windsor  soap,  404 

perfumes  for,  441 
Whitening  tallow,  470 


INDEX. 


581 


Whittaker's  patent  soap  frame,  232,  233 

remelter,  381,  382 
Wick  machine,  continuous,  512,  513 
Wicks  and  their  preparation,  488-493 
apparatus  for  soaking  and  cutting, 

492,  493 
for  dipped  candles,  494 
for  stearic  acid  candles,  517 
machines  for  cutting,  490,  491 
plaiting  and  gimping  of,  493 
Windsor  soap,  404 
musk,  417 
old  brown,  406 
rose,  416 
violet,  417 
white,  404 

perfumes  for,  441 
Wilson,  George,  saponification  by,  of 
fats  by  water  and  distillation, 
479,  480 

Wilson's   process,  rendering   lard  by 
steam,  88-90 


Wine  measure,  U.  S.,  545 
Wiutergreen  oil,  446-447 
Woad,  oil  of,  98 

Wood  ashes,  boiling  with,  312,  313 

potash  lye  from,  253,  254 
Wood,  frames  of,  233-236 
Wool,  fat  train,  136 

utilization  of,  132-139 
washing,  soaps  for,  195 
Woollens,  ox-gall  soap   for  scouring, 
384 

Yarns,  mode  of  designating  the  fine- 
ness of,  489,  490 
Yellow  ochre,  falsification  of  yellow 
wax  with,  loO 
silicic  soap,  331,  332 
soap,  285-287,  404 
Swiss  soap,  307 

Zinc  soap,  156 


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AMATEUR  MECHANICS'  WORKSHOP: 

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BARR.— A  Practical  Treatise  on  the  Combustion  of  Coal: 
Including  descriptions  of  various  mechanical  devices  for  the  Eco- 
nomic Generation  of  Heat  by  the  Combustion  of  Fuel,  whether  solid, 
liquid  or  gaseous.    8vo.    .......  ^2.50 

BARR. — A  Practical  Treatise  on  High  Pressure  Steam  Boilers : 
Including  Results  of  Recent  Experimental  Tests  of  Boiler  Materials, 
together  with  a  Description  of  Approved  Safety  Apparatus,  Steam 
Pumps,  Injectors  and  Economizers  in  actual  use.  By  Wm.  M.  Barr. 
204  Illustrations.    8vo  $3-00 

BAUERMAN.— A  Treatise  on  the  Metallurgy  of  Iron : 

Containing  Outlines  of  the  History  of  Iron  Manufacture,  Methods  of 
Assay,  and  Analysis  of  Iron  Ores,  Processes  of  Manufacture  of  Iron 
and  Steel,  etc.,  etc.  By  H.  Bauerman,  F.  G.  S.,  Associate  of  the 
Royal  School  of  Mines.  Fifth  Edition,  Revised  and  Enlarged. 
Illustrated  with  numerous  Wood  Engravings  from  Drawings  by  J.  B. 
Jordan.    i2mo  $2.00 

BAYLES. — House  Drainage  and  Water  Service : 

In  Cities,  Villages  and  Rural  Neighborhoods.  With  Incidental  Con. 
sideration  of  Certain  Causes  Affecting  the  Healthfulness  of  Dwell- 
ings. By  James  C.  Bayles,  Editor  of  "  The  Iron  Age  "  and  "  The 
Metal  Worker."    With  numerous  illustrations.    8vo.  cloth,  ^3.00 

BEANS.— A  Treatise  on  Railway  Curves  and  Location  of 
Railroads: 

By  E.  W.  Beans,  C.  E.    Illustrated.    i2mo.    Tucks      .  ^1.50 
BECKETT.— A  Rudimentary  Treatise  on  Clocks,  and  Watches 
and  Bells  : 

By  Sir  Edmund  Beckett,  Bart.,  LL.  D.,  Q.  C.  F.  R.  A.  S.  With 
numerous  illustrations.  Seventh  Edition,  Revised  and  Enlarged. 
l2mo  ^2.25 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


BELL. — Carpentry  Made  Easy: 

Or,  The  Science  and  Art  of  Framing  on  a  New  and  Improved 
System.  With  Specific  Instructions  for  Building  Balloon  Frames,  Barn 
Frames,  Mill  Frames,  Warehouses,  Church  Spires,  etc.  Comprising 
also  a  System  of  Bridge  Building,  with  Bills,  Estimates  of  Cost,  and 
valuable  Tables.  Illustrated  by  forty-four  plates,  comprising  nearly 
200  figures.  By  William  E.  Bell,  Architect  and  Practical  Builder. 
8vo  $S-oo 

BEMROSE. — Fret-Cutting  and  Perforated  Carving: 

With  fifty-three  practical  illustrations.  By  W.  Bemrose,  Jr.  I  vol. 
quarto  $3-0° 

BEMROSE. — Manual  of  Buhl-work  and  Marquetry: 

With  Practical  Instructions  for  Learners,  and  ninety  colored  designs. 
By  W.  Bemrose,  Jr.    i  vol.  quarto         ....  $3-oo 

BEMROSE.— Manual  of  Wood  Carving: 

With  Practical  Illustrations  for  Learners  of  the  Art,  and  Original  and 
Selected  Designs.  By  William  Bemrose,  Jr.  With  an  Intro- 
duction by  Llewellyn  Jewitt,  F.  S.  A.,  etc.  With  128  illustra- 
tions, 4to.  ^3-oo 

BILLINGS.— Tobacco : 

Its  History,  Variety,  Culture,  Manufacture,  Commerce,  and  Various 
Modes  of  Use.  By  E.  R.  Billings.  Illustrated  by  nearly  200 
engravings.    Svo.     ........  $3-'^o 

BIRD. — The  American  Practical  Dyers'  Companion: 

Comprising  a  Description  of  the  Principal  Dye-Stuffs  and  Chemicals 
used  in  Dyeing,  their  Natures  and  Uses ;  Mordants,  and  How  Made ; 
with  the  best  American,  English,  French  and  German  processes  for 
Bleaching  and  Dyeing  Silk,  Wool,  Cotton,  Linen,  Flannel,  Felt, 
Dress  Goods,  Mixed  and  Hosiery  Yarns,  Feathers,  Grass,  Felt,  Fur, 
Wool,  and  Straw  Hats,  Jute  Yarn,  Vegetable  Ivory,  Mats,  Skins, 
Furs,  Leather,  etc.,  etc.  By  Wood,  Aniline,  and  other  Processes, 
together  with  Remarks  on  Finishing  Agents,  and  Instructions  in  the 
Finishing  of  Fabrics,  Substitutes  for  Indigo,  Water- Proofing  of 
Materials,  Tests  and  Purification  of  Water,  Manufacture  of  Aniline 
and  other  New  Dye  Wares,  Harmonizing  Colors,  etc.,  etc. ;  embrac- 
ing in  all  over  800  Receipts  for  Colors  and  Shades,  accompanied  by 
170  Dyed  Samples  of  Raw  Materials  and  Fabrics.  By  F.  J.  BiRD, 
Practical  Dyer,  Author  of  "  The  Dyers'  Hand-Book."    Svo.  ^10.00 

BLENKARN. — Practical  Specifications  of  Works  executed  in 
Architecture,  Civil  and  Mechanical  Engineering,  and  in 
Road  Making  and  Sewering : 
To  which  are  added  a  series  of  practically  useful  Agreements  and 
Reports.    By  John  Blenkarn.    Illustrated  by  fifteen  large  folding 
plates.    Svo  ^9.00 

BLINN. — A  Practical  Workshop  Companion  for  Tin,  Sheet- 
Iron,  and  Copper-plate  Workers  : 
Containing  Rules  for  describing  various  kinds  of  Patterns  used  by 
Tin,  Sheet-Iron  and  Copper-plate  Workers;  Practical  Geometry; 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


5 


Mensuration  of  Surfaces  and  Solids ;  Tables  of  the  Weights  of 
Metals,  Lead-pipe,  etc.;  Tables  of  Areas  and  Circumferences 
of  Circles;  Japan,  Varnishes,  Lackers,  Cements,  Compositions,  etc., 
etc.  By  Leroy  J.  Blinn,  Master  Mechanic.  With  over  One 
Hundred  Illustrations.    i2mo.  ^^2.50 

BOOTH. — Marble  Worker's  Manual  : 

Containing  Practical  Information  respecting  Marbles  in  general,  their 
Cutting,  Working  and  Polishing ;  Veneering  of  Marble  ;  Mosaics  ; 
Composition  and  Use  of  Artificial  Marble,  Stuccos,  Cements,  Receipts, 
Secrets,  etc.,  etc.  Translated  from  the  French  by  M.  L.  Booth. 
With  an  Appendix  concerning  American  Marbles.  i2mo.,  cloth  $1.50 

BOOTH  and  MORFIT.— The  Encyclopaedia  of  Chemistry, 
Practical  and  Theoretical : 
Embracing  its  application  to  the  Arts,  Metallurgy,  Mineralogy, 
Geology,  Medicine  and  Pharmacy.  By  James  C.  Booth,  Melter 
and  Refiner  in  the  United  States  Mint,  Professor  of  Applied  Chem- 
istry in  the  Franklin  Institute,  etc.,  assisted  by  Campbell  Morfit, 
author  of  "  Chemical  Manipulations,"  etc.  Seventh  Edition.  Com- 
plete in  one  volume,  royal  8vo.,  978  pages,  with  numerous  wood-cuts 
and  other  illustrations       .......  ^5.00 

BRAMWELL.— The  Wool  Carder's  Vade-Mecum  : 

A  Complete  Manual  of  the  Art  of  Carding  Textile  Fabrics.  By  W. 
C.  Bramwell.  Third  Edition,  revised  and  enlarged.  Illustrated, 
pp.  400.    l2mo  ^^2.50 

BRANNT.— The  Techno-Chemical  Receipt  Book  : 

Containing  several  thousand  Receipts  comprising  the  latest  and  most 
useful  discoveries  in  Chemical  Technology  and  Industry.  Edited 
from  the  German  of  Drs.  E.  Winckler,  Heintze  and  Mierzinski, 
with  additions  by  W.  T.  Brannt.    [In  preparation.) 

BROWN. — Five  Hundred  and  Seven  Mechanical  Movements: 
Embracing  all  those  which  are  most  important  in  Dynamics,  Hy- 
draulics, Hydrostatics,  Pneumatics,  Steam-Engines,  Mill  and  other 
Gearing,  Presses,  Horology  and  Miscellaneous  Machinery;  and  in- 
cluding many  movements  never  before  published,  and  several  of 
which  have  only  recently  come  into  use.  By  Henry  T.  Brown. 
i2mo  j^i.oo 

BUCKMASTER.— The  Elements  of  Mechanical  Physics  : 
By  J.  C.  BucKMASTER.      Illustrated  with  numerous  engravings. 
l2mo  ^1.50 

BULLOCK.— The  American  Cottage  Builder  : 

A  Series  of  Designs,  Plans  and  Specifications,  from  ^200  to  ^20,000, 
for  Homes  for  the  People;  together  with  Warming,  Ventilation, 
Drainage,  Painting  and  Landscape  Gardening.  By  John  Bullock, 
Architect  and  Editor  of  "The  Rudiments  of  Architecture  and 
Building,"  etc.,  etc.    Illustrated  by  75  engravings.    8vo.  S3. 50 

BULLOCK. — The  Rudiments  of  Architecture  and  Building : 
For  the  use  of  Architects,  Builders,  Draughtsmen,  Machinists,  En- 
gineers and  Mechanics.    Edited  by  John  Bullock,  author  of  "  The 
American  Cottage  Builder."  Illustrated  by  250  Engravings.  Svo.  ^3.50 


6  HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


BURGH. — Practical   Rules   for  the  Proportions  of  Modern 
Engines  and  Boilers  for  Land  and  Marine  Purposes. 

By  N.  P.  Burgh,  Engineer.  i2mo.  .  .  .  .  $1.50 
BURNS.— The  American  Woolen  Manufacturer: 

A  Practical  Treatise  on  the  Manufacture  of  Woolens,  in  two  parts. 
Part  First  gives  full  and  explicit  instructions  upon  Drafting,  Cross- 
Drawing,  Combining  Weaves,  and  the  correct  arrangement  of  Weights, 
Colors  and  Sizes  of  Yarns  to  produce  any' desired  fabric.  Illustrated 
with  diagrams  of  various  weavings,  and  twelve  samples  of  cloth  for 
explanation  and  practice.  Part  Second  is  fully  supplied  with  ex- 
tended Tables,  Rules,  Examples,  Explanations,  etc. ;  gives  full  and 
practical  information,  in  detailed  order,  from  the  stock  department  to 
the  market,  of  the  proper  selection  and  use  of  the  various  grades  and 
staples  of  wool,  with  the  admixture  of  waste,  cotton  and  shoddy;  and 

•  the  proper  application  and  economical  use  of  the  various  oils,  drugs, 
dye  stuffs,  soaps,  belting,  etc.  Also,  the  most  approved  method  for 
Calculating  and  Estimating  the  Cost  of  Goods,  for  all  Wool,  Wool 
Waste  and  Cotton  and  Cotton  Warps.  With  Examples  and  Calcula- 
tions on  the  Circular  motions  of  Wheels,  Pinions,  Drums,  Pulleys 
and  Gears,  how  to  speed  them,  etc.  The  two  parts  combined  form  a 
whole  work  on  the  American  way  of  manufacturing  more  complete 
than  any  yet  issued.    By  George  C.  Burns.    8vo.  .       ,  ^6.50 

BYLES. — Sophisms   of    Free   Trade   and   Popular  Political 
Economy  Examined. 
By  a  Barrister  (Sir  John  Barnard  Byles,  Judge  of  Common 
Pleas).     From  the  Ninth  English  Edition,  as  published  by  the 
Manchester  Reciprocity  Association.    i2mo.     .       .        .  ^1.25 

BYRN. — The  Complete  Practical  Brewer: 

Or  Plain,  Accurate  and  Thorough  Instructions  in  the  Art  of  Brewing 
Beer,  Ale,  Porter,  including  the  Process  of  Making  Bavarian  Beer, 
all  the  Small  Beers,  such  as  Root-beer,  Ginger-pop,  Sarsaparilla-beer, 
Mead,  Spruce  Beer,  etc.  Adapted  to  the  use  of  Public  Brewers  and 
Private  Families.  By  M.  La  Fayette  Byrn,  M.  D.  With  illus- 
trations. i2mo. 

BYRN.— The  Complete  Practical  Distiller: 

Comprising  the  most  perfect  and  exact  Theoretical  and  Practical  De- 
scription of  the  Art  of  Distillation  and  Rectification;  including  all  of 
the  most  recent  improvements  in  distilling  apparatus;  instructions  for 
preparing  spirits  from  the  numerous  vegetables,  fruits,  etc  ;  directions 
for  the  distillation  and  preparation  of  all  kinds  of  brandies  and  other 
spirits,  spirituous  and  other  compounds,  etc.  By  M.  La  Fayette 
Byrn,  M.  D.  Eighth  Edition.  To  which  are  added  Practical 
Directions  for  Distilling,  from  the  French  of  Th.  Fling,  Brewer  and 
Distiller.    i2mo  •        •        •  $^-SO 

BYRNE. — Hand-Book  for  the  Artisan,  Mechanic,  and  Engi- 
neer : 

Comprising  the  Grinding  and  Sharpening  of  Cutting  Tools,  Abrasive 
Processes,  Lapidary  Work,  Gem  and  Glass  Engraving,  Varnishing 
and  Lackering,  Apparatus,  Materials  and  Processes  for  Grinding  and 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


Polishing,  etc.  By  Oliver  Byrne.  Illustrated  by  185  wood  en- 
gravings.   8vo.  ^5.00 

BYRNE.— Pocket-Book  for  Railroad  and  Civil  Engineers  : 

Containing  New,  Exact  and  Concise  Methods  for  Laying  out  Railroad 
Curves,  Switches,  Frog  Angles  and  Crossings ;  the  Staking  out  of 
work;  Levelling;  the  Calculation  of  Cuttings;  Embankments;  Earth- 
work, etc.  By  Oliver  Byrne.  i8mo.,  full  bound,  pocket-book 
form  ^1-75 

BYRNE.— The  Practical  Metal-Worker's  Assistant: 

Comprising  Metallurgic  Chemistry;  the  Arts  of  Working  all  Metals 
and  Alloys;  Forging  of  Iron  and  Steel;  Hardening  and  Tempering  ; 
Melting  and  Mixing;  Casting  and  Founding  ;  Works  in  Sheet  Metal; 
the  Processes  Dependent  on  the  Ductility  of  the  Metals;  Soldering; 
and  the  most  Improved  Processes  and  Tools  employed  by  Metal- 
W^orkers.  With  the  Application  of  the  Art  of  Electro-Metallurgy  to 
Manufacturing  Processes;  collected  from  Original  Sources,  and  from 
the  works  of  Holtzapffel,  Bergeron,  Leupold,  Plumier,  Napier, 
Scoffern,  Clay,  Fairbairn  and  others.  By  Oliver  Byrne,  A  new, 
revised  and  improved  edition,  to  which  is  added  an  Appendix,  con- 
taining The  Manufacture  of  Russian  Sheet-Iron,  By  John  Percy, 
M.  D.,  F,  R.  S,  The  Manufacture  of  Malleable  Iron  Castings,  and 
Improvements  in  Bessemer  Steel.  By  A.  A.  Fesquet,  Chemist  and 
Engineer.  With  over  Six  Hundred  Engravings,  Illustrating  every 
Branch  of  the  Subject.    8vo  ^7-00 

BYRNE.— The  Practical  Model  Calculator: 

For  the  Engineer,  Mechanic,  Manufacturer  of  Engine  Work,  Naval 
Architect,  Miner  and  Millwright.  By  Oliver  Byrne.  8vo.,  nearly 
600  pages  ^4.50 

CABINET  MAKER'S  ALBUM  OF  FURNITURE: 

Comprising  a  Collection  of  Designs  for  various  Styles  of  Furniture. 
Illustrated  by  Forty-eight  Large  and  Beautifully  Engraved  Plates. 
Oblong,  8vo  ^3.50 

CALLINGHAM.— Sign  Writing  and  Glass  Embossing: 

A  Complete  Practical  Illustrated  Manual  of  the  Art.  By  James 
Callingham,    i2mo  $1.50 

CAMPIN. — A  Practical  Treatise  on  Mechanical  Engineering : 
Comprising  Metallurgy,  Moulding,  Casting,  Forging,  Tools,  Work- 
shop Machinery,  Mechanical  Manipulation,  Manufacture  of  Steam- 
Engines,  etc.  With  an  Appendix  on  the  Analysis  of  Iron  and  Iron 
.  Ores.  By  Francis  Campin,  C.  E.  To  which  are  added.  Observations 
on  the  Construction  of  Steam  Boilers,  and  Remarks  upon  Furnaces 
used  for  Smoke  Prevention ;  with  a  Chapter  on  Explosions.  By  R. 
Armstrong,  C.  E,,  and  John  Bourne.  Rules  for  Calculating  the 
Change  Wheels  for  Screws  on  a  Turning  Lathe,  and  for  a  Wheel- 
cutting  Machine,  By  J.  La  Nicca.  Management  of  Steel,  Includ- 
ing p'orging.  Hardening,  Tempering,  Annealing,  Shrinking  and 
Expansi  )n  ;  and  the  Case-hardening  of  Iron.  By  G,  Ede,  8vo, 
Illustrated  with  twenty-nine  plates  and  100  wood  engravings  ^5.00 


8 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


CAREY.— A  Memoir  of  Henry  C.  Carey. 

By  Dr.  Wm.  Elder.   With  a  portrait.    8vo.,  cloth       .       .  75 

CAREY.— The  Works  of  Henry  C.  Carey  : 

Harmony  of  Interests  :  Agricultural,  Manufacturing  and  Commer- 
cial.   8vo.   ^i-5o 

Manual  of  Social  Science.  Condensed  from  Carey's  "  Principles 
of  Social  Science."  By  KatE  McKean.  I  vol.  l2mo.  .  ^2.25 
Miscellaneous  Works.    With  a  Portrait.   2  vols.  8vo.  ^6.00 

Past,  Present  and  Future.    Svo  ^^2.50 

Principles  of  Social  Science.  3  volumes,  Svo.  .  .  ^10.00 
The  Slave-Trade,  Domestic  and  Foreign;  Why  it  Exists,  and 
How  it  may  be  Extinguished  (1853).  8vo.  .  .  .  ^2.00 
The  Unity  of  Law :  As  Exhibited  in  the  Relations  of  Physical, 
Social,  Mental  and  Moral  Science  (1872).    Svo.       .        .  ^3.50 

CLARK. — Tramways,  their  Construction  and  Working : 

Embracing  a  Comprehensive  History  of  the  System.  With  an  ex- 
haustive analysis  of  the  various  modes  of  traction,  including  horse- 
power, steam,  heated  water  and  compressed  air;  a  description  of  the 
varieties  of  Rolling  stock,  and  ample  details  of  cost  and  working  ex- 
penses. By  D.  KiNNEAR  Clark.  Illustrated  by  over  200  wood 
engravings,  and  thirteen  folding  plates,    2  vols.    Svo.       .  ^12.50 

COLBURN.— The  Locomotive  Engine  : 

Including  a  Description  of  its  Structure,  Rules  for  Estimating  its 
Capabilities,  and  Practical  Observations  on  its  Construction  and  Man- 
agement.   By  Zerah  CoLBURN.    Illustrated.    i2mo.       .  ^i.oo 

COLLENS.— The  Eden  of  Labor;  or,  the  Christian  Utopia. 
By  T.  Wharton  Collens,  author^of  "  Humanics,"  "  The  History 
of  Charity,"  etc.    i2mo.    Paper  cover,  ^i. 00 ;  Cloth        .  ^1.25 

COOLEY.— A  Complete  Practical  Treatise  on  Perfumery : 

Being  a  Hand-book  of  Perfumes,  Cosmetics  and  other  Toilet  Articles. 
With  a  Comprehensive  Collection  of  Formulae.  By  Arnold  J. 
CooLEY.   i2mo  ^1.50 

COOPER.— A  Treatise  on  the  use  of  Belting  for  the  Trans- 
mission of  Power. 
With  numerous  illustrations  of  approved  and  actual  methods  of  ar- 
ranging Main  Driving  and  Quarter  Twist  Belts,  and  of  Belt  Fasten- 
ings. Examples  and  Rules  in  great  number  for  exhibiting  and  cal- 
culating the  size  and  driving  power  of  Belts.  Plain,  Particular  and 
Practical  Directions  for  the  Treatment,  Care  and  Management  of 
Belts.  Descriptions  of  many  varieties  of  Beltings,  together  with 
chapters  on  the  Transmission  of  Power  by  Ropes ;  by  Iron  and 
Wood  Frictional  Gearing;  on  the  Strength  of  Belting  Leather;  and 
on  the  Experimental  Investigations  of  Morin,  Briggs,  and  others.  By 
John  H.  Cooper,  M.  E.  Svo  ^3-5o 

CRAIK.— The  Practical  American  Millwright  and  Miller. 

By  David  Craik,  Millwright.  Illustrated  by  numerous  wood  en- 
gravings and  two  folding  plates.    Svo.  -    .       .       .       .  j^5-00 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


9 


CRISTIANI. — A  Technical  Treatise  on  Soap  and  Candles: 

With  a  Glance  at  the  Industry  of  Fats  and  Oils.  By  R.  S.  Cris- 
TIANI,  Chemist.  Author  of  "  Perfumery  and  Kindred  Arts."  Illus- 
trated by  176  engravings.    581  pages,  8vo.       .       .        .  ^7.50 

CRISTIANI.— Perfumery  and  Kindred  Arts: 

A  Comprehensive  Treatise  on  Perfumery,  containing  a  History  of 
Perfumes  from  the  remotest  ages  to  the  present  time.  A  complete 
detailed  description  of  the  various  Materials  and  Apparatus  used  in 
the  Perfumer's  Art,  v^^ith  thorough  Practical  Instruction  and  careful 
Formulae,  and  advice  for  the  fabrication  of  all  known  preparations  of 
the  day,  including  Essences,  Tinctures,  Extracts,  Spirits,  Waters, 
Vinegars,  Pomades,  Powders,  Paints,  Oils,  Emulsions,  Cosmetics, 
Infusions,  Pastilles,  Tooth  Powders  and  Washes,  Cachous,  Hair  Dyes, 
Sachets,  Essential  Oils,  Flavoring  Extracts,  etc. ;  and  full  details  for 
making  and  manipulating  Fancy  Toilet  Soaps,  Shaving  Creams,  etc., 
by  new  and  improved  methods.  With  an  Appendix  giving  hints  and 
advice  for  making  and  fermenting  Domestic  Wines,  Cordials,  Liquors, 
Candies,  Jellies,  Syrups,  Colors,  etc.,  and  for  Perfuming  and  Flavor- 
ing Segars,  Snuff  and  Tobacco,  and  Miscellaneous  Receipts  for 
various  useful  Analogous  Articles.  By  R.  S.  Cristiani,  Con- 
sulting Chemist  and  Perfumer,  Philadelphia.    8vo.    .       .  ^5.00 

CROOKES.— A  Practical  Hand-Book  of  Dyeing  and  Calico 
Printing. 

By  Wm.  Crookes,  F.  R.  S.,  etc.  With  eleven  page  plates,  forty- 
seven  specimens  of  Dyed  and  Printed  Fabrics,  and  thirty-eight  wood 

cuts.    730  pages,  8vo  ^15.00 

CROOKES.— Select  Methods  in  Chemical  Analysis  (chiefly 
inorganic). 

By  Wm.  Crookes,  F.  R.  S.    Illustrated  with  twenty-two  wood  cuts. 

1 2mo.,  468  pages       .   ^5.00 

CUPPER.— The  Universal  Stair-Builder : 

Being  a  new  Treatise  on  the  Construction  of  Stair-Cases  and  Hand- 
Rails;  showing  Plans  of  the  various  forms  of  Stairs,  method  of 
Placing  the  Risers  in  the  Cylinders,  general  method  of  describing 
the  Face  Moulds  for  a  Hand-Rail,  and  an  expeditious  method  of 
Squaring  the  Rail.  Useful  also  to  Stonemasons  constructing  Stone 
Stairs  and  Hand-Rails  ;  with  a  new  method  of  Sawing  the  Twist 
Part  of  any  Hand-Rail  square  from  the  face  of  the  plank,  and  to  a 
parallel  width.  Also,  a  new  method  of  forming  the  Easings  of  the 
Rail  by  a  gauge ;  preceded  by  some  necessary  Problems  in  Practical 
Geometry,  with  the  Sections  of  Prismatic  Solids.  Illustrated  by  29 
plates.  By  R.  A.  Cupper,  Architect,  author  of  "  The  Practical 
Stair-Builder's  Guide."  Third  Edition.  Large  4to.  .  ^2.50 
DAVIDSON.— A  Practical  Manual  of  House  Painting,  Grain- 
ing, Marbling,  and  Sign- Writing : 
Containing  full  information  on  the  processes  of  House  Painting  in 


i 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE, 


Oil  and  'Distemper,  the  Formation  of  Letters  and  Practice  of  Sign- 
Writing,  the  Principles  of  Decorative  Art,  a  Course  of  Elementary 
Drawing  for  House  Painters,  Writers,  etc.,  and  a  Collection  of  Useful 
Receipts.  With  nine  colored  illustrations  of  Woods  and  Marbles, 
and  numerous  wood  engravings.    By  Ellis  A.  Davidson.  i2mo. 

$300 

DAVIES. — A  Treatise  on  Metalliferous  Minerals  and  Mining: 

By  D.  C.  Davies,  F.  G.  S.,  Mining  Engineer,  Examiner  of  Mines, 
Quarries  and  Collieries.  Illustrated  by  148  engravings  of  Geological 
Formations,  Mining  Operations  and  Machinery,  drawn  from  the 
practice  of  all  parts  of  the  world.  2d  Edition,  i2mo.,  450  pages  ^5.00 

DAVIES. — A  Treatise  on  Slate  and  Slate  Quarrying: 

Scientific,  Practical  and  Commercial.  By  D.  C.  Davies,  F.  G.  S., 
Mining  Engineer,  etc.  With  numerous  illustrations  and  folding 
plates.    i2mo.         ........  $2.50 

DAWIDOWSKY— BRANNT.— A  Practical  Treatise  on  the 
Fabrication  of  Glue,  Gelatine,  Cements,  Pastes,  Mucilages, 
etc.: 

Comprising  a  Popular  Description  of  these  Industries,  based  upon 
Practical  Experience.    By  F.  Dawidowsky,  Technical  Chemist. 
From  the  German,  with  additions,  by  WiLLiAM  T.  Brannt.  Illus- 
trated.    l2mo.   {/n  preparation.') 
DE  GRAFF.— The  Geometrical  Stair-Builders'  Guide: 

Being  a  Plain  Practical  System  of  Hand-Railing,  embracing  all  its 
necessary  Details,  and  Geometrically  Illustrated  by  twenty-two  Steel 
Engravings ;  together  with  the  use  of  the  most  approved  principles 
of  Practical  Geometry.     By  Simon  De  Graff,  Architect.  4to. 

^2.50 

DE  KONINCK— DIETZ.— A  Practical  Manual  of  Chemical 
Analysis  and  Assaying : 

As  applied  to  the  Manufacture  of  Iron  from  its  Ores,  and  to  Cast  Iron, 
Wrought  Iron,  and  Steel,  as  found  in  Commerce.  By  L.  L.  De 
KoNiNCK,  Dr.  Sc.,  and  E.  Dietz,  Engineer.  Edited  with  Notes,  by 
Robert  Mallet,  F.  R.  S.,  F.  S.  G.,  M.  I.  C.  E.,  etc.  American 
Edition,  Edited  with  Notes  and  an  Appendix  on  Iron  Ores,  by  A.  A. 
Fesquet,  Chemist  and  Engineer.    i2mo.         .       .       .  ^2.50 

DUNCAN.— Practical  Surveyor's  Guide: 

Containing  the  necessary  information  to  make  any  person  of  com- 
mon capacity,  a  finished  land  surveyor  without  the  aid  of  a  teacher. 
By  Andrew  Duncan.    Illustrated,    i2mo.     .       .       .  ^1.25 

DUPLAIS. — A  Treatise  on  the  Manufacture  and  Distillation 
of  Alcoholic  Liquors : 
Comprising  Accurate  and  Complete  Details  in  Regard  to  Alcohol 
from  Wine,  Molasses,  Beets,  Grain,  Rice,  Potatoes,  Sorghum,  Aspho- 
del, Fruits,  etc. ;  with  the  Distillation  and  Rectification  of  Brandy, 
Whiskey,  Rum,  Gin,  Swiss  Absinthe,  etc.,  the  Preparation  of  Aro- 
matic Waters,  Volatile  Oils  or  Essences,  Sugars,  Syrups,  Aromatic 
Tinctures,  Liqueurs,  Cordial  Wines,  Effervescing  Wines,  etc.,  the 


HENRY  CAREY  BAIRD  &  CO^S  CATALOGUE.  n 


Ageing  of  Brandy  and  the  improvement  of  Spirits,  with  Copious 
Directions  and  Tables  for  Testing  and  Reducing  Spirituous  Liquors, 
etc.,  etc.  Translated  and  Edited  from  the  French  of  MM.  DuPLAis, 
Aine  et  Jeune.  By  M.  McKennie,  M.  D.  To  which  are  added  the 
United  States  Internal  Revenue  Regulations  for  the  Assessment  and 
Collection  of  Taxes  on  Distilled  Spirits.  Illustrated  by  fourteen 
folding  plates  and  several  wood  engravings-.    743  pp.  8vo.       $10  00 

DUSSAUCE.— A  General  Treatise  on  the  Manufacture  of 
Every  Description  of  Soap  : 
Comprising  the  Chemistry  of  the  Art,  with  Remarks  on  Alkalies, 
Saponifiable  Fatty  Bodies,  the  apparatus  necessary  in  a  Soap  Factory, 
Practical  Instructions  in  the  manufacture  of  the  various  kinds  of 
Soap,  the  assay  of  Soaps,  etc.,  etc.  By  Prof.  H.  Dussauce,  Chemist. 
Illustrated.    8vo  ^25  00 

DUSSAUCE.— A  General  Treatise  on  the  Manufacture  of 
Vinegar: 

Theoretical  and  Practical.  Comprising  the  various  Methods,  by  the 
Slow  and  the  Quick  Processes,  with  Alcohol,  Wine,  Grain,  Malt, 
Cider,  Molasses,  and  Beets ;  as  well  as  the  Fabrication  of  Wood 
Vinegar,  etc.,  etc.    By  Prof.  H.  Dussauce.    8vo.  .       ^5  00 

DUSSAUCE.— A  New  and  Complete  Treatise  on  the  Arts  of 
Tanning,  Currying,  and  Leather  Dressing  : 
Comprising  all  the  Discoveries  and  Improvements  made  in  France, 
Great  Britain,  and  the  United  States.  Edited  from  Notes  and 
Documents  of  Messrs.  Sallerou,  Grouvelle,  Duval,  Dessables,  Labar- 
raque,  Payen,  Rene,  De  Fontenelle,  Malapeyre,  etc.,  etc.  By  Prof. 
H.  Dussauce,  Chemist.  Illustrated  by  212  wood  engravings. 
8vo.  $25  00 

DUSSAUCE.— Practical  Treatise  on  the  Fabrication  of  Matches, 
Gun  Cotton,  and  Fulminating  Powder. 
By  Professor  H.  Dussauce.    i2mo.        .       .       .       .       $3  00 

DYER  AND  COLOR-MAKER'S  COMPANION: 

Containing  upwards  of  two  hundred  Receipts  for  making  Colors,  on 
the  most  approved  principles,  for  all  the  various  styles  and  fabrics  now 
in  existence ;  with  the  Scouring  Process,  and  plain  Directions  for 
Preparing,  Washing-ofF,  and  Finishing  the  Goods.    i2mo.       $i  25 

EASTON.— A  Practical  Treatise  on  Street  or  Horse-Power 
Railways  : 

By  Alexander  Easton,  C.  E.  Illustrated  by  23  plates.  8vo.  ^3  00 
EDWARDS.— A  Catechism  of  the  Marine  Steam-Engine, 

For  the  use  of  Engineers,  Firemen,  and  Mechanics.  A  Practical 
Work  for  Practical  Men.  By  Emory  Edwards,  Mechanical  Engi- 
neer. Illustrated  by  sixty-three  Engravings,  including  examples  of 
the  most  modern  Engines.  Third  edition,  thoroughly  revised,  with 
much  additional  matter.  1 2  mo.  414  pages  .  .  .  ^2  00 
EDWARDS. — Modern  American  Locomotive  Engines, 

Their  Design,  Construction  and  Management.  By  Emory  Edwards. 
Illustrated  i2mo  


12        HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


EDWARDS. — Modern  American  Marine  Engines,  Boilers,  and 
Screw  Propellers, 

Their  Design  and  Construction.  Showing  the  Present  Practice  of 
the  most  Eminent  Engineers  and  Marine  Engine  Builders  in  the 
United  States.  Ilhistrated  by  30  large  and  elaborate  plates.  4to.  ^5.00 

EDWARDS.— The  Practical  Steam  Engineer's  Guide 

In  the  Design,  Construction,  and  Management  of  American  Stationary, 
Portable,  and  Steam  Fire-Engines,  Steam  Pumps,  Boilers,  Injectors, 
Governors,  Indicators,  Pistons  and  Rings,  Safety  Valves  and  Steam 
Gauges.  For  the  use  of  Engineers,  Firemen,  and  Steam  Users.  By 
Emory  Edwards.  Illustrated  by  119  engravings.  420  pages. 
l2mo   $2  50 

ELDER. — Conversations  on  the  Principal  Subjects  of  Political 
Economy. 

By  Dr.  William  Elder.  8vo  ^2  50 

ELDER.— Questions  of  the  Day, 

Economic  and  Social.  By  Dr.  William  Elder,  8vo.  .  go 
ELDER.— Memoir  of  Henry  C.  Carey. 

By  Dr.  William  Elder.  8vo.  cloth   75 

ERNL — Mineralogy  Simplified. 

Easy  Methods  of  Determining  and  Classifying  Minerals,  including 
Ores,  by  means  of  the  Blowpipe,  and  by  Humid  Chemical  Analysis, 
based  on  Professor  von  Kobell's  Tables  for  the  Determination  of 
Minerals,  with  an  Introduction  to  Modern  Chemistry.  By  Henry 
Erni,  A.m.,  M.D.,  Professor  of  Chemistry.  Second  Edition,  rewritten, 
enlarged  and  improved.  i2mo.    (7«  presj.) 

FITCH.— Bessemer  Steel, 

Ores  and  Methods,  New  Facts  and  Statistics  Relating  to  the  Types 
of  Machinery  in  Use,  the  Methods  in  Vogue,  Cost  and  Class  of  Labor 
employed,  and  the  Character  and  Availability  of  the  Ores  utilized  in 
the  Manufacture  of  Bessemer  Steel  in  Europe  and  in  the  United  States; 
together  with  opinions  and  excerpts  from  various  accepted  authorities. 
Compiled  and  arranged  by  Thomas  W.  Fitch.  8vo.       .       ^3  00 

FLEMING.— Narrow  Gauge  Railways  in  America. 

A  Sketch  of  their  Rise,  Progress,  and  Success.  Valuable  Statistics 
as  to  Grades,  Curves,  Weight  of  Rail,  Locomotives,  Cars,  etc.  By 
Howard  Fleming.    Illustrated,  8vo  ^150 

FORSYTH.— Book  of  Designs  for  Headstones,  Mural,  and 
other  Monuments : 
Containing  78  Designs.    By  James  Forsyth.  With  an  Introduction 
by  Charles  Boutell,  M.  A.    4  to.,  cloth     .       .       .  $S 

FRANKEL— HUTTER.— A  Practical  Treatise  on  the  Manu- 
facture of  Starch,  Glucose,  Starch- Sugar,  and  Dextrine  : 
Based  on  the  German  of  Ladislaus  Von  Wagner,  Professor  in  the 
Royal  Technical  High  School,  Buda-Pest,  Hungary,  and  other 
authorities.  By  Julius  Frankel,  Graduate  of  the  Polytechnic 
School  of  Hanover.  Edited  by  Robert  Hutter,  Chemist,  Practical 
Manufacturer  of  Starch-Sugar,  Proprietor  of  the  Philadelphia  Starch- 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


Sugar  Works.    Illustrated  by  58  engravings,  covering  every  branch 
of  the  subject,  including  examples  of  the  most  recent  and  best  Ameri- 
can machinery.  8vo.,  344  pp.  .....  ^3.50 

FRAZIER. — Modern  Processes  in  the  Metallurgy  of  Iron  and 
Steel : 

By  B.  W.  Frazier,  Professor  of  Mining  and  Metallurgy  in  Lehigh 
University,  Bethlehem,  Pa.  Elaborately  Illustrated.  (/«  prepar- 
ation.) 

GEE. — The  Practical  Gold  Worker  : 

Or,  the  Goldsmith's  and  Jeweller's  Instructor  in  the  Art  of  Alloying, 
Melting,  Reducing,  Coloring,  Collecting,  and  Refining;  the  Processes 
of  Manipulation,  Recovery  of  Waste,  Chemical  and  Physical  Proper- 
ties of  Gold,  with  a  New  System  of  Mixing  its  Alloys,  Solders, 
Enamels,  and  other  Useful  Rules  and  Recipes.    By  George  E. 

Gee.   i2mo  $1.75 

GEE.— The  Silversmith's  Handbook  : 

Containing  full  instructions  for  the  Alloying  and  Working  of  Silver, 
including  the  different  modes  of  Refining  and  Melting  the  Metal ;  its 
Solders  ;  the  Preparation  of  Imitation  Alloys ;  Methods  of  Manipula- 
tion ;  Prevention  of  Waste;  Instructions  for  Improving  and  Finishing 
the  Surface  of  the  Work  ;  together  with  other  Useful  Information  and 
Memoranda.    By  George  E.  Gee,  Jeweller.    Illustrated.  i2mo. 

^1-75 

GOTHIC  ALBUM  FOR  CABINET-MAKERS: 

Designs  for  Gothic  Furniture.    Twenty-three  plates.   Oblong  ^2.00 

GREGORY.— Mathematics  for  Practical  Men  : 

Adapted  to  the  Pursuits  of  Surveyors,  Architects,  Mechanics,  and 
Civil  Engineers.    By  Olinthus  Gregory.    8vo.,  plates  .  ^3.00 

GRIER.— Rural  Hydraulics : 

A  Practical  Treatise  on  Rural  Household  Water  Supply.  Giving  a 
full  description  of  Springs  and  Wells,  of  Pumps  and  Hydraulic  Ram, 
with  Instructions  in  Cistern  Building,  Laying  of  Pipes,  etc.  By  W. 
W.  Grier.    Illustrated  8vo.      ......  75 

GRIMSHAW.— Modern  Milling: 

Being  the  substance  of  two  addresses  delivered  by  request,  at  the 
Franklin  Institute,  Philadelphia,  January  19th  and  January  27th, 
1881.  By  Robert  Grimshaw,  Ph.  D.  Edited  from  the  Phono- 
graphic Reports.    With  28  Illustrations.    8vo.         .       .  ^i.oo 

GRIMSHAW.— Saws : 

The  History,  Development,  Action,  Classification,  and  Comparison 
of  Saws  of  all  kinds.  With  Copious  Appendices.  Giving  the  details 
of  Manufacture,  Filing,  Setting,  Gumming,  etc.  Care  and  Use  of 
Saws;  Tables  of  Gauges;  Capacities  of  Saw-Mills;  List  of  Saw- 
Patents,  and  other  valuable  information.  By  Robert  Grimshaw. 
Second  and  greatly  enlarged  edition,  with  Supplejuent,  and  354  Illus- 
trations.   Quarto      ........  ^4.00 

GRIMSHAW. — A  Supplement  to  Grimshaw  on  Saws  : 

Containing  additional  practical  matter,  more  especially  relating  to  the 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


P'orms  of  Saw-Teeth,  for  special  material  and  conditions,  and  to  the 
Behavior  of  Saws  under  particular  conditions.    120  Illustrations.  By 

Robert  Grimshaw.    Quarto  $2.00 

GRISWOLD. — Railroad  Engineer's  Pocket  Companion  for  the 
Field : 

Comprising  Rules  for  Calculating  Deflection  Distances  and  Angles, 
Tangential  Distances  and  Angles,  and  all  Necessary  Tables  for  En- 
gineers; also  the  Art  of  Levelling  from  Preliminary  Survey  to  the 
Construction  of  Railroads,  intended  Expressly  for  the  Young  En- 
gineer, together  with  Numerous  Valuable  Rules  and  Examples.  By 
W.  Gris-wold.    lamo.,  tucks  $^-7S 

GRUNER.— Studies  of  Blast  Furnace  Phenomena: 

By  M.  L.  Gruner,  President  of  the  General  Council  of  Mines  of 
France,  and  lately  Professor  of  Metallurgy  at  the  Ecole  des  Mines. 
Translated,  with  the  author's  sanction,  with  an  Appendix,  by  L.  D. 
B.  Gordon,  F,  R.  S.  E.,  F.  G.  S.    8vo.  .       .       .  ^2.50 

GUETTIER.— Metallic  Alloys: 

Being  a  Practical  Guide  to  their  Chemical  and  Physical  Properties, 
their  Prejxiration,  Composition,  and  Uses.  Translated  from  the 
F'rench  of  A.  Guettier,  Engineer  and  Director  of  Founderies, 
author  of  "  La  Fouderie  en  France,"  etc.,  etc.  By  A.  A.  Fesquet, 
Chemist  and  Engineer.     l2mo.  .....  $3-00 

HASERICK.— The  Secrets  of  the  Art  of  Dyeing  Wool,  Cotton, 
and  Linen, 

Including  Bleaching  and  Coloring  Wool  and  Cotton  Hosiery  and 
Random  Yarns.  A  Treatise  based  on  Economy  and  Practice.  By 
E.  C.  Haserick.  Illustrated  by  323  Dyed  Patterns  of  the  Yarns 
or  Fabrics.   8vo,       ........  ^25.00 

HATS  AND  FELTING: 

A  Practical  Treatise  on  their  Manufacture.  By  a  Practical  Hatter. 
Illustrated  by  Drawings  of  Machinery,  etc.    8vo.      .       .  ^1.25 

HEINZERLING.— Elements  of  the  Fabrication  of  Leather, 
with  Special  Regard  to  the  Latest  Improvements  in  this  Branch  of 
Industry.  A  Manual  for  Tanners,  Technologists,  Etc.  By  Dr.  Chris- 
tian Heinzerling.  Translated  from  the  German  by  William  T. 
Brannt,  Graduate  of  the  Royal  Agricultural  College  of  Eldena, 
Prussia;  With  additions  by  an  American  Editor.  Illustrated  by 
numerous  Engravings.  Svo.    (/« preparation.) 

HENRY.— The  Early  and  Later  History  of  Petroleum: 

With  Authentic  Facts  in  regard  to  its  Development  in  Western  Penn- 
sylvania. With  Sketches  of  the  Pioneer  and  Prominent  Operators, 
together  with  the  Refining  Capacity  of  the  United  States.  By  J.  T. 
Henry.    Illustrated  Svo.  M-So 

HOFFER.— A  Practical  Treatise  on  Caoutchouc  and  Gutta 
Percha, 

Comprising  the  Properties  of  the  Raw  Materials,  and  the  manner  of 
Mixing  and  Working  them;  with  the  Fabrication  of  Vulcanized  and 
Hard  Rubbers,  Caoutchouc  and  Gutta  Percha  Compositions,  Water- 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.  15 


proof  Substances,  Elastic  Tissues,  the  Utilization  of  Waste,  etc.,  etc. 
From  the  German  of  Raimund  Hoffer.  By  W.  T.  Brannt. 
Illustrated  i2mo  $2.50 

HOFMANN. — A  Practical  Treatise  on  the  Manufacture  of 
Paper  in  all  its  Branches  : 
By  Carl  Hofmann,  Late  Superintendent  of  Paper-Mills  in  Germany 
and  the  United  Slates;  recently  Manager  of  the  "Public  Ledger" 
Paper-Mills,  near  Elkton,  Maryland.  Illustrated  by  no  wood  en- 
gravings, and  five  large  Folding  Plates.  4to.,  cloth;  about  400 
pages        ..........  ^20.00 

HUGHES. — American  Miller  and  Millwright's  Assistant: 
Hy  William  Carter  Huc.HEs.    i2nK).    ....  $1.50 

HULME. — Worked  Examination  Questions  in  Plane  Geomet- 
rical Drawing  : 

For  the  Use  of  Candidates  for  the  Royal  Military  Academy,  Wool- 
wich; the  Royal  Military  College,  Sandhurst ;  the  Indian  Civil  En- 
gineering College,  Cooper's  Hill  ;  Indian  Public  Works  and  Tele- 
graph Departments ;  Royal  Marine  Light  Infantry;  the  Oxford  and 
Cambridge  Local  Examinations,  etc.  By  F.  Edward  Hulmf,  F.  L. 
S.,  F.  S.  A.,  Art-Master  Marlborough  College.  Llustraled  by  300 
examples.    Small  quarto  ......  ^3-75 

HURST. — A  Hand-Book  for  Architectural  Surveyors  and  others 
Engaged  in  Building: 
Containing  Formulae  useful  in  Designing  Builders'  Work,  Table  of 
Weights,  of  the  Materials  used  in  Building,  Memoranda  connected 
with  Builders'  Work,  Mensuration,  the  Practice  of  Builders'  Measure- 
ment, Contracts  of  Labor,  Valuation  of  Property,  Summary  of  the 
Practice  in  Dilapidation,  etc.,  etc.  By  J.  F.  Hdrst,  C.  E.  Second 
edition,  pocket-book  form,  full  bound       ....  $2.00 

JERVIS.— Railroad  Property: 

A  Treatise  on  the  Construction  and  Management  of  Railways; 
designed  to  afford  useful  knowledge,  in  the  popular  style,  to  the 
holders  of  this  class  of  property  ;  as  well  as  Railway  Managers,  Offi- 
cers, and  Agents.  By  John  B.  Jervis,  late  Civil  Engineer  of  the 
Hudson  River  Railroad,  Croton  Aqueduct,  etc.   i2mo.,c}oth  ^2.00 

KEENE.— A  Hand-Book  of  Practical  Gauging: 

For  the  Use  of  Beginners,  to  which  is  added  a  CTiapter  on  Distilla- 
tion, describing  the  process  in  operation  at  the  Custf^m- House  for 
ascertaining  the  Strength  of  Wines.  By  James  B.  KpENE,  of  H.  M. 
Customs.   '8vo.         .       .       ,  ^1.25 

KELLEY.— Speeches,  Addresses,  and  Letters  on  Industrial  ap4 
Financial  Questions  : 
By  Hon.  William  D.  Kei.ley,  M.  C.    544  pages,  8vo.  .  ^3-oo 

KELLOGG.— A  New  Monetary  System  : 

The  only  means  of  Securing  the  respective  Rights  of  Labor  au4 
Property,  and  of  Protecting  the  Public  from  Financial  Revulsiops. 
By  Edward  Kellogq.  Revised  from  his  work  on  "Labor  and 
other  Capital."    With  numerous  additions  frprn   his  mnnuspriptf 


i6        HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


Edited  by  Mary  Kellogg  Putnam.    Fifth  edition.    To  which  is 
added  a  Biographical  Sketch  of  the  Author.    One  volume,  i2mo. 
Paper  cover      .........  $i.oo 

Bound  in  cloth         ........         1. 50 

KEMLO.— Watch-Repairer's  Hand-Book : 

Being  a  Complete  Guide  to  the  Young  Beginner,  in  Taking  Apart, 
Putting  Together,  and  Thoroughly  Cleaning  the  English  Lever  and 
other  Foreign  Watches,  and  all  American  Watches.  By  F.  Kemlo, 
Practical  Watchmaker.    With  Illustrations.     l2mo.  .  ^1.25 

KENTISH.— A  Treatise  on  a  Box  of  Instruments, 

And  the  Slide  Rule;  with  the  Theory  of  Trigonometry  and  Loga- 
rithms, including  Practical  Geometry,  Surveying,  Measuring  of  Tim- 
ber, Cask  and  Malt  Gauging,  Heights,  and  Distances.  By  THOMAS 
Kentish.    In  one  volume.    i2mo.  .       .       .       .  ^1.25 

KERL.— The  Assayer's  Manual: 

An  Abri  Iged  Treatise  on  the  Docimastic  Examination  of  Ores,  and 
Furnac-;  and  other  Ariiticial  Products.  By  Bruno  Kerl,  Professor 
in  the  Royal  School  of  Mines ;  Member  of  the  Royal  Technical 
Commi>.>i  )n  for  the  Industries,  and  r.f  the  Imperial  Patent-Office, 
Berlin.  Translated  from  the  German  by  William  T.  Brannt, 
Graduate  of  the  Royal  Agricultural  College  of  Eldena,  Prussia. 
Edited  by  William  H.  Wahl,  Ph.  D.,  Secretary  of  the  Franklin 
Institute,  Philadelphia.    Illustrated  by  sixty-five  engravings.  8vo. 

$3-00 

KINGZETT.— The  History,  Products,  and  Processes  of  the 
Alkali  Trade : 

Including  the  most  Recent  Improvements.  By  Charles  Thomas 
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KINSLEY. — Self-Instructor  on  Lumber  Surveying: 

For  the  Use  of  Lumber  Manufacturers,  Surveyors,  and  Teachers, 
By  Charles  Kinsley,  Practical  Surveyor  and  Teacher  of  Surveying. 
l2mo  ^2.00 

KIRK.— The  Founding  of  Metals: 

A  Practical  Treatise  on  the  Melting  of  Iron,  with  a  Description  of  the 
Founding  of  Alloys;  also,  of  nil  the  Metals  and  Mineral  Substances 
used  in  the  Art  of  P^ounding.  Collected  from  original  sources.  By 
Edward  Kirk,  Practical  Foundryman  and  Chemist.  Illustrated. 
Third  edition.    8vo.  ^2,50 

KITTREDGE.— The  Compendium  of   Architectural  Sheet- 
Metal  Work : 

Profusely  Illustrated.  Embracing  Rules  and  Directions  for  Estimates, 
Items  of  Cost,  Nomenclature,  Tal)les  of  Brackets,  Modillions,  Den- 
tals, Trusses,  Stop-Blocks,  Frieze  Pieces,  etc.  Architect's  Specifica- 
tion, Tables  of  Tin-Roofing,  Galvanized  Iron,  etc.,  etc.  To  which  is 
added  the  Exemplar  of  Architectural  Sheet-Metal  Work,  containing 
details  of  the  Centennial  Buildings,  and  other  important  Sheet-Metal 
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HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


17 


pany,  and  a  Catalogue  of  Cornices,  Window-Caps,  Mouldings,  etc.,  as 
manufactured  by  the  Kittredge  Cornice  and  Ornament  Company. 
The  whole  supplemented  by  a  full  Index  and  Table  of  Contents.  By 
A.  O.  Kittredge.   8vo.,  565  pages         ....  ^5.00 

LANDRIN.— A  Treatise  on  Steel: 

Comprising  its  Theory,  Metallurgy,  Properties,  Practical  Working, 
and  Use.  By  M.  H.  C.  Landrin,  Jr.,  Civil  Engineer.  Translated 
from  the  French,  with  Notes,  by  A.  A.  Fesquet,  Chemist  and  En- 
gineer. With  an  Appendix  on  the  Bessemer  and  the  Martin  Pro- 
cesses for  Manufacturing  Steel,  from  the  Report  of  Abram  vS.  Hewitt, 
United  States  Commissioner  to  the  Universal  Exposition,  Paris,  1867. 
l2mo  $3.00 

LARDEN.~A  School  Course  on  Heat : 

By  W.  Larden,  M.  A.    321  pp.  i2mo  ^^2.00 

LARDNER.— The  Steam-Engine  ; 

For  the  Use  of  Beginners.   By  Dr.  Lardner.  Illustrated.  i2mo. 

75 

LARKIN. — The  Practical  Brass  and  Iron  Founder's  Guide: 

A  Concise  Treatise  on  Brass  Founding,  Moulding,  the  Metals  and 
their  Alloys,  etc.;  to  which  are  added  Recent  Improvements  in  the 
Manufacture  of  Iron,  Steel  by  the  Bessemer  Process,  etc.,  etc.  By 
James  Larkin,  late  Conductor  of  the  Brass  Foundry  Department  in 
Reany,  Neafie  &  Co.'s  Penn  Works,  Philadelphia.  Fifth  edition, 
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LEROUX.— A  Practical  Treatise  on  the  Manufacture  of 
Worsteds  and  Carded  Yarns  : 
Comprising  Practical  Mechanics,  with  Rules  and  Calculations  applied 
to  Spinning;  Sorting,  Cleaning,  and  Scouring  Wools;  the  English 
and  French  Methods  of  Combing,  Drawing,  and  Spinning  Worsteds, 
and  Manufacturing  Carded  Yarns.  Translated  from  the  French  of 
Charles  Leroux,  Mechanical  Engineer  and  Superintendent  of  a 
Spinning-Mill,  by  Horatio  Paine,  M.  D.,  and  A.  A.  Fesquet, 
Chemist  and  Engineer.  Illustrated  by  twelve  large  Plates.  To  which 
is  added  an  Appendix,  containing  Extracts  from  the  Reports  of  the 
International  Jury,  and  of  the  Artisans  selected  by  the  Committee 
appointed  by  the  Council  of  the  Society  of  Arts,  London,  on  Woolen 
and  Worsted  Machinery  and  Fabrics,  as  exhibited  in  the  Paris  Uni- 
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LEFFEL. — The  Construction  of  Mill-Dams  : 

Comprising  also  the  Building  of  Race  and  Reservoir  Embankments 
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Supply,  etc.  By  James  Leffel  &  Co.  Illustrated  by  58  engravings. 
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LESLIE.— Complete  Cookery: 

Directions  for  Cookery  in  its  Various  Branches.  By  Miss  Leslie. 
Sixtieth  thousand.    Thoroughly  revised,  with  the  addition  of  New 

Receipts.    In  i2mo.,  cloth  $i-50 

2 


i8        HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


LIEBER.— Assayer's  Guide  : 

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Tests  and  Assays,  by  Heat  and  by  Wet  Processes,  for  the  Ores  of  all 
the  principal  Metals,  of  Gold  and  Silver  Coins  and  Alloys,  and  of 
Coal,  etc.    By  Oscar  M.  Lieber.    i2mo.       .       .       .  $1.25 

LOVE. — The  Art  of  Dyeing,  Cleaning,  Scouring,  and  Finish- 
ing, on  the  Most  Approved  English  and  French  Methods; 
Being  Practical  Instructions  in  Dyeing  Silks,  Woolens,  and  Cottons, 
Feathers,  Chips,  Straw,  etc.  Scouring  and  Cleaning  Bed  and  Win- 
dow Curtains,  Carpets,  Rugs,  etc.  French  and  English  Cleaning, 
any  Color  or  Fabric  of  Silk,  Satin,  or  Damask.  By  Thomas  Love, 
a  Working  Dyer  and  Scourer.  Second  American  Edition,  to  which 
are  added  General  Instructions  for  the  use  of  Aniline  Colors.  8vo. 
343  pages  ^5.00 

LUKIN. — Amongst  Machines: 

Embracing  Descriptions  of  the  various  Mechanical  Appliances  used 
in  the  Manufacture  of  Wood,  Metal,  and  other  Substances.  i2mo. 

^1-75 

LUKIN.— The  Boy  Engineers: 

What  They  Did,  and  How  They  Did  It.    With  30  plates.  l8mo. 

^1-75 

LUKIN.— The  Young  Mechanic  c 

Practical  Carpentry.  Containing  Directions  for  the  Use  of  all  kinds 
of  Tools,  and  for  Construction  of  Steam- Engines  and  Mechanical 
Models,  including  the  Art  of  Turning  in  Wood  and  Metal.  By  John 
LuKiN,  Author  of  "The  Lathe  and  Its  Uses,"  etc.  Illustrated. 
l2mo  ^1.75 

MAIN  and  BROWN.— Questions  on  Subjects  Connected  with 
the  Marine  Steam-Engine : 
And    Examination    Papers;    with    Hints    for   their  Solution.  By 
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and  Thomas  Brown,  Chief  Engineer,  R.  N.    i2mo.,  cloth  .  ^1.50 

MAIN  and  BROWN. — The  Indicator  and  Dynamometer: 
With  their  Practical  Applications  to  the  Steam-Engine.    By  Thomas 
J.  Main,  M.  A.  F.  R.,  Ass't  S.  Professor  Royal  Naval  College, 
Portsmouth,  and  Thomas  Brown,  Assoc.  Inst.  C.  E.,  Chief  Engineer 
R.  N.,  attached  to  the  R.  N.  College.    Illustrated.    8vo.  .  ^1.50 

MAIN  and  BROWN.— The  Marine  Steam-Engine. 

By  Thomas  J.  Main,  F.  R.  Ass't  S.  Mathematical  Professor  at  the 
Royal  Naval  College,  Portsmouth,  and  Thomas  Brown,  Assoc. 
Inst.  C.  E.,  Chief  Engineer  R.  N.  Attached  to  the  Royal  Naval 
College.    With  numerous  illustrations.    8vo.     .       .       .  ^5.00 

MARTIN.— Screw-Cutting  Tables,  for  the  Use  of  Mechanical 
Engineers  : 

Showing  the  Proper  Arrangement  of  Wheels  for  Cutting  the  Threads 
of  Screws  of  any  Required  Pitch;  with  a  Table  for  Making  the  Uni- 
versal Gas-Pipe  Thread  and  Taps.  By  W.  A.  Martin,  Engineer. 
8vo   50 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


MICHELL.— Mine  Drainage: 

Being  a  Complete  and  Practical  Treatise  on  Direct-Acting  Under- 
ground Steam  Pumping  Machinery.  With  a  Description  of  a  large 
number  of  the  best  known  Engines,  their  General  Utility  and  the 
Special  Sphere  of  their  Action,  the  Mode  of  their  Application,  and 
their  Merits  compared  with  other  Pumping  Machinery.  By  Stephen 
MiCHELL.   Illustrated  by  137  engravings.   8vq.,  277  pages  .  ^6.00 

MOLESWORTH.— Pocket-Book   of    Useful    Formulae  and 
Memoranda  for  Civil  and  Mechanical  Engineers. 
By  Guilford  L.  Molesworth,  Member  of  the  Institution  of  Civil 
Engineers,  Chief  Resident  Engineer  of  the  Ceylon  Railway.  Full- 
bound  in  Pocket-book  form      ......  ^i.oo 

MOORE.— The  Universal  Assistant  and  the  Complete  Me- 
chanic : 

Containing  over  one  million  Industrial  Facts,  Calculations,  Receipts, 
Processes,  Trades  Secrets,  Rules,  Business  Forms,  Legal  Items,  Etc., 
in  every  occupation,  from  the  Household  to  the  Manufactory.  By 
R.  Moore.    Illustrated  by  500  Engravings.    i2mo.         .  ^2,50 

MORRIS. — Easy  Rules  for  the  Measurement  of  Earthworks  : 
By  means  of  the  Prismoidal  Formula.  Illustrated  with  Numerous 
Wood-Cuts,  Problems,  and  Examples,  and  concluded  by  an  Exten- 
sive Table  for  finding  the  Solidity  in  cubic  yards  from  Mean  Areas. 
The  whole  being  adapted  for  convenient  use  by  Engineers,  Surveyors, 
Contractors,  and  others  needing  Correct  Measurements  of  Earthwork. 
By  Elwood  Morris,  C.  E.    8vo  ;^i.50 

MORTON. — The  System  of  Calculating  Diameter,  Circumfer- 
ence, Area,  and  Squaring  the  Circle  : 
Together  with  Interest  and  Miscellaneous  Tables,  and  other  informa- 
tion.   By  James  Morton.     Second  Edition,  enlarged,  with  the 
Metric  System.    i2mo.     .......  ^i.oo 

NAPIER.— Manual  of  Electro-Metallurgy: 

Including  the  Application  of  the  Art  to  Manufacturing  Processes, 
By  James  Napier.  Fourth  American,  from  the  Fourth  London 
edition,  revised  and  enlarged.    Illustrated  by  engravings.  8vo.  ^1.50 

NAPIER. — A  System  of  Chemistry  Applied  to  Dyeing. 

By  James  Napier,  F.  C.  S.  A  New  and  Thoroughly  Revised  Edi- 
tion. Completely  brought  up  to  the  present  state  of  the  Science, 
including  the  Chemistry  of  Coal  Tar  Colors,  by  A.  A.  Fesquet, 
Chemist  and  Engineer.  With  an  Appendix  on  Dyeing  and  Calico 
Printing,  as  shown  at  the  Universal  Exposition,  Paris,  1867.  Illus- 
trated. 8vo,  422  pages  ^5-oo 

NEVILLE.— Hydraulic  Tables,  Coefficients,  and  Formulae,  for 
finding  the  Discharge  of  Water  from  Orifices,  Notches, 
Weirs,  Pipes,  and  Rivers: 
Third  Edition,  with  Additions,  consisting  of  New  Formulas  for  the 
Discharge  from  Tidal  and  Flood  Sluices  and  Siphons ;  general  infor- 
mation on  Rainfall,  Catchment-Basins,  Drainage,  Sewerage,  Water 
Supply  for  Towns  and  Mill  Power.    By  John  Neville,  C.  E.  M.  R. 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


I.  A. ;  Fellow  of  the  Royal  Geological  Society  of  Ireland.  Thick 

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NEWBERY.— Gleanings    from    Ornamental    Art  of  every 
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1862,  and  the  best  English  and  Foreign  works.  In  a  series  of  100 
exquisitely  drawn  Plates,  containing  many  hundred  examples.  By 
Robert  Newbery.  410.  $12.50 

NICHOLLS.  —The  Theoretical  and  Practical  Boiler-Maker  and 
Engineer's  Reference  Book:  • 
Containing  a  variety  of  Useful  Information  for  Employers  of  Labor, 
Foremen  and  Working  Boiler-Makers,  Iron,  Copper,  and  Tinsmiths, 
Draughtsmen,  Engineers,  the  General  Steam-using  Public,  and  for  the 
Use  of  Science  Schools  and  Classes.  By  Samuel  NicholLS.  Illus- 
trated by  sixteen  plates,  i2mo.  .        .        .        .        .  $2.50 

NICHOLSON.— A  Manual  of  the  Art  of  Bookbinding : 

Containing  full  instructions  in  the  different  Branches  of  Forwarding, 
Gilding,  and  Finishing.  Also,  the  Art  of  Marbling  Book-edges  and 
Paper.    By  James  B.  Nicholson.    Illustrated.  i2mo.,  cloth  $2.25 

NICOLLS.— The  Railway  Builder: 

A  Hand-Book  for  Estimating  the  Probable  Cost  of  American  Rail- 
way Construction  and  Equipment.  By  William  J.  Nicolls,  Civil 
Engineer.  Illustrated,  full  bound,  pocket-book  form         .  $2.00 

NORMANDY.— The  Commercial  Handbook  of  Chemical  An- 
alysis : 

Or  Practical  Instructions  for  the  Determination  of  the  Intrinsic  or 
Commercial  Value  of  Substances  used  in  Manufactures,  in  Trades, 
and  in  the  Arts.  By  A.  Normandy.  New  Edition,  Enlarged,  and 
to  a  great  extent  rewritten.    By  Henry  M.  Noad,  Ph.D.,  F.R.S., 

thick  l2mo  $5.00 

NORRIS. — A  Handbook  for  Locomotive  Engineers  and  Ma- 
chinists : 

Comprising  the  Proportions  and  Calculations  for  Constructing  Loco- 
motives; Manner  of  Setting  Valves;  Tables  of  Squares,  Cubes,  Areas, 
etc.,  etc.  3y  Septimus  Norris,  M.  E.  New  edition.  Illustrated, 
l2mo  ^1.50 

NORTH.— The  Practical  Assayer: 

Containing  Easy  Methods  for  the  Assay  of  the  Principal  Metals  and 
Alloys.  Principally  designed  for  explorers  and  those  interested  in 
Mines.    By  Oliver  North.    Illustrated.    i2mo.  .  ^2.50 

NYSTROM.— A  New  Treatise  on  Elements  of  Mechanics  : 
Establishing  Strict  Precision  in  the  Meaning  of  Dynamical  Terms : 
accompanied  with  an  Appendix  on  Duodenal  Arithmetic  and  Me- 
trology.   By  John  W.  Nystrom,  C.  E.    Illustrated.    Svo.  ;^2.oo^ 

NYSTROM.— On  Technological  Education  and  the  Construc- 
tion of  Ships  and  Screw  Propellers : 
For  Naval  and  Marine  Engineers.    By  John  W.  Nystrom,  late 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


Acting  Chief  Engineer,  U.  S,  N.  Second  edition,  revised,  with  addi- 
tional matter.    Illustrated  by  seven  engravings.    i2mo.    ,  ^1.50 

O'NEILL. — A  Dictionary  of  Dyeing  and  Calico  Printing: 

Containing  a  brief  account  of  all  the  Substances  and  Processes  in 
use  in  the  Art  of  Dyeing  and  Printing  Textile  Fabrics  ;  with  Practical 
Receipts  and  Scientific  Information.  By  Charles  O'Neill,  Analy- 
tical Chemist.  To  which  is  added  an  Essay  on  Coal  Tar  Colors  and 
their  application  to  Dyeing  and  Calico  Printing.  By  A.  A.  Fesquet, 
Cheniist  and  Engineer.  With  an  appendix  on  Dyeing  and  Calico 
Printing,  as  shown  at  the  Universal  Exposition,  Paris,  1867.  8vo., 
491  pages  ^5.00 

ORTON. — Underground  Treasures: 

How  and  Where  to  Find  Them.  A  Key  for  the  Ready  Determination 
of  all  the  Useful  Minerals  within  the  United  Slates.  By  James 
Orton,  A.m.,  Late  Professor  of  Natural  History  in  Vassar  College, 
N.  Y.;  Cor.  Mem.  of  the  Academy  of  Natural  Sciences,  Philadelphia, 
and  of  the  Lyceum  of  Natural  History,  New  York ;  author  of  the 
Andes  and  the  Amazon,"  etc.  A  New  Edition,  with  Additions. 
Illustrated        .........  ^^1.50 

OSBORN.— The  Metallurgy  of  Iron  and  Steel: 

Theoretical  and  Practical  in  all  its  Branches;  with  special  reference 
to  American  Materials  and  Processes.  By  H.  S.  OsBORN,  LL.  D., 
Professor  of  Mining  and  Metallurgy  in  Lafayette  College,  Easton, 
Pennsylvania.  Illustrated  by  numerous  large  folding  plates  and 
wood-engravings.    Svo.  ......  ^25.00 

OVERMAN.— The  Manufacture  of  Steel : 

Containing  the  Practice  and  Principles  of  Working  and  Making  Steel. 
A  Handbook  for  Blacksmiths  and  Workers  in  Steel  and  Iron,  Wagon 
Makers,  Die  Sinkers,  Cutlers,  and  Manufacturers  of  Files  and  Hard- 
ware, of  Steel  and  Iron,  and  for  Men  of  Science  and  Art.  By 
Frederick  Overman,  Mining  Engineer,  Author  of  the  "  Manu- 
facture of  Iron,"  etc.  A  new,  enlarged,  and  revised  Edition.  By 
A.  A.  Fesquet,  Chemist  and  Engineer.    i2mo.       .       .  ^1.50 

OVERMAN.— The  Moulder's  and  Founder's  Pocket  Guide  : 
A  Treatise  on  Moulding  and  Founding  in  Green-sand,  Dry-sand,  Loam, 
and  Cement;  the  Moulding  of  Machine  Frames,  Mill-gear,  Hollow- 
ware,  Ornaments,  Trinkets,  Bells,  and  Statues;  Description  of  Moulds 
for  Iron,  Bronze,  Brass,  and  other  Metals;  Plaster  of  Paris,  Sulphur, 
Wax,  etc. ;  the  Construction  of  Melting  Furnaces,  the  Melting  and 
Founding  of  Metals  ;  the  Composition  of  Alloys  and  their  Nature, 
etc.,  etc.  By  Frederick  Overman,  M,  E,  A  new  Edition,  to 
which  is  added  a  Supplement  on  Statuary  and  Ornamental  Moulding, 
Ordnance,  Malleable  Iron  Castings,  etc.  By  A.  A.  Fesquet,  Chem- 
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PAINTER,  GILDER,  AND  VARNISHER'S  COMPANION  : 
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of  Painting,  Gilding,  Varnishing,  Glass-Staining,  Graining,  Marbling, 
Sign-Wriimg,  Gilding  on  Glass,  and  Coach  Painting  and  Varnishing; 


22        HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


Tests  for  the  Detection  of  Adulterations  in  Oils,  Colors,  etc. ;  and  a 
Statement  of  the  Diseases  to  which  Painters  are  peculiarly  liable,  with 
the  Simplest  and  Best  R-emedies.  Sixteenth  Edition.  Revised,  with 
an  Appendix.  Containing  Colors  and  Coloring — Theoretical  ai\G 
Practical.  Comprising  descriptions  of  a  great  variety  of  Additional 
Pigments,  their  Qualities  and  Uses,  to  which  are  added,  Dryers,  and* 
Modes  and  Operations  of  Painting,  etc.  Together  with  Chevreui's 
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PALLETT.— The  Miller's,  Millwright's,  and  Engineer's  Guide. 
By  Henry  Pallett.    Illustrated.    i2mo.      .       .       .  ^3.00 

PEARSE. — A  Concise  History  of  the  Iron  Manufacture  of  the 
American  Colonies  up  to  the  Revolution,  and  of  Pennsyl- 
vania until  the  present  time. 
By  John  B.  Pearse.    Illustrated  i2mo.  .       .       .  ^2.00 

PERCY. — The  Manufacture  of  Russian  Sheet-Iron. 

By  John  Percy",  M.  D.,  F.  R.  S.,  Lecturer  on  Metallurgy  at  the 
Royal  School  of  Mines,  and  to  The  Advance  Class  of  Artillery 
Officers  at  the  Royal  Artillery  Institution,  Woolwich;  Author  of 
"  Metallurgy."  With  Illustrations.    8vo.,  paper      .        .        50  cts, 

PERKINS.— Gas  and  Ventilation  : 

Practical  Treatise  on  Gas  and  Ventilation.  With  Special  Relation 
to  Illuminating,  Heating,  and  Cooking  by  Gas.  Including  Scientific 
Helps  to  Engineer-students  and  others.  With  Illustrated  Diagrams. 
By  E.  E.  Perkins.    i2mo.,  cloth  ^1.2"; 

PERKINS  AND  STOWE.— A  New  Guide  to  the  Sheet-iron 
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Containing  a  Series  of  Tables  showing  the  Weight  of  Slabs  and  Piles 
to  Produce  Boiler  Plates,  and  of  the  Weight  of  Piles  and  the  Sizes  of 
Bars  to  produce  Sheet-iron ;  the  Thickness  of  the  Bar  Gauge 
in  decimals;  the  Weight  per  foot,  and  the  Thickness  on  the  Bar  or 
Wire  Gauge  of  the  fractional  parts  of  an  inch;  the  Weight  per 
sheet,  and  the  Thickness  on  the  Wire  Gauge  of  Sheet-iron  of  various 
dimensions  to  weigh  1 12  lbs.  per  bundle;  and  the  conversion  of 
Short  Weight  into  Long  Weight,  and  Long  Weight  into  Short. 
Estimated  and  collected  by  G.  H.  Perkins  and  J.  G.  Stowe.  ^2.50 

POWELL— CHANCE— HARRIS.— The  Principles  of  Glass 
Making, 

By  Harry  J.  Powell,  B.  A.  Together  with  Treatises  on  Crown  and 
Sheet  Glass;  by  Henry  Chance,  M.  A.    And  Plate  Glass,  by  H. 
G.  Harris,  Asso.  M.  Inst.  C.  E.    Illustrated  i8mo.        .  ^1.50 
PROTEAUX.— Practical  Guide  for  the  Manufacture  of  Paper 
and  Boards. 

By  A.  Proteaux.  From  the  French,  by  Horatio  Paine,  A,  B., 
M.  D.  To  which  is  added  the  Manufacture  of  Paper  from  Wood, 
by  Henry  T.  Brown.  Illustrated  by  six  plates.  8vo.  .  $12.50 
PROCTOR.— A  Pocket-Book  of  Useful  Tables  and  Formulae 
for  Marine  Engineers. 
By  Frank  Proctor.  Second  Edition,  Revised  and  Enlarged. 
Full  bound  pocket-book  form    ......  $1.50 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.  23 


REGNAULT.— Elements  of  Chemistry. 

By  M.  V.  Regnault.  Translated  from  the  French  by  T.  Forrest 
Betton,  M.  D.,  and  edited,  with  Notes,  by  James  C.  Booth,  Melter 
and  Refiner  U.  S.  Mint,  and  William  L.  Faber.  Metallurgist  and 
Mining  Engineer.  Illustrated  by  nearly  700  wood  engravings.  Com- 
prising nearly  1,500  pages.    In  two  volumes,  8vo.,  cloth    .  ^7.50 

ROPER. — A  Catechism  of  High-Pressure,  or  Non-Condensing 
Steam-Engines  : 
Including  the  Modelling,  Constructing,  and  Management  of  Steam- 

»  Engines  and  Steam  Boilers.  With  valuable  illustrations.  By  Ste- 
phen Roper,  Engineer.  Sixteenth  edition,  revised  and  enlarged. 
i8mo.,  tucks,  gilt  edge  ^2.00 

ROPER.— Engineer's  Handy-Book: 

Containing  a  full  Explanation  of  the  Steam-Engine  Indicator,  and  its 
Use  and  Advantages  to  Engineers  and  wSteam  Users.  With  Formulae 
for  Estimating  the  Power  of  all  Classes  of  Steam-Engines;  also, 
Facts,  Figures,  Questions,  and  Tables  for  Engineers  who  wish  to 
qualify  themselves  for  the  United  States  Navy,  the  Revenue  Service, 
the  Mercantile  Marine,  or  to  take  charge  of  the  Better  Class  of  Sta- 
tionary Steam-Engines.  Sixth  edition.  i6mo.,  690  pages,  tucks, 
gilt  edge  $3.50 

ROPER. — Hand-Book  of  Land  and  Marine  Engines  : 

Including  the  Modelling,  Construction,  Running,  and  Management 
of  Land  and  Marine  Engines  and  Boilers.  With  illustrations.  By 
Stephen  Roper,  Engineer.   Sixth  edition.    i2mo.,  tucks,  gilt  edge. 

^3-50 

ROPER.— Hand-Book  of  the  Locomotive  : 

Including  the  Construction  of  Engines  and  Boilers,  and  the  Construc- 
tion, Management,  and  Running  of  Locomotives.    By  Stephen 


Roper.    Eleventh  edition.     i8mo.,  tucks,  gilt  edge  .  ^2.50 

ROPER.— Hand-Book  of  Modern  Steam  Fire-Engines. 

With  illustrations.    By  STEPHEN  RoPER,  Engineer.    Fourth  edition, 

i2mo.,  tucks,  gilt  edge      .......  ^3-50 

ROPER. — Questions  and  Answers  for  Engineers. 

This  little  book  contains  all  the  Que^^tions  that  Engineers  will  be 


asked  when  undergoing  an  Examination  for  the  purpose  of  procuring 
Licenses,  and  they  are  so  plain  that  any  Engineer  or  Fireman  of  or- 
dinary intelligence  may  commit  them  to  memory  in  a  short  time.  By 
Stephen  Roper,  Engineer.    Third  edition      .       .       .  $3.00 

ROPER.— Use  and  Abuse  of  the  Steam  Boiler. 

By  Stephen  Roper,  Engineer.  Eighth  edition,  with  illustrations. 
l8mo.,  tucks,  gilt  edge      .......  $2.00 

ROSE.— The  Complete  Practical  Machinist : 

Embracing  Lathe-Work,  Vise- Work,  Drills  and  Drilling,  Taps  and 
Dies,  Hardening  and  Tempering,  the  Making  and  Use  of  Tools,  Tool 
Grinding,  Marking  Out  Work,  etc.  By  JosHUA  Rose,  Author  of  "  The 
Pattern-maker's  Assistant"  and  "The  Slide  Valve."  Illustrated  by 
196  engravings.  Eighth  edition,  revised  and  enlarged  by  the  addition 
of  much  new  matter.    I2mc.,  441  pages  .       .       .  ^^2.50 


24        HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


ROSE,— Mechanical  Drawing  Self-Taught: 

Comprising  Instructions  in  the  Selection  and  Preparation  of  Drawing 
Instruments,  Elementary  Instruction  in  Practical  Mechanical  Draw- 
ing, together  with  Examples  in  Simple  Geometry  and  Elementary 
Mechanism,  including  Screw  Threads,  Gear  Wheels,  Mechanical  Mo- 
tions, Engines  and  Boilers.  By  JosHUA  Rose,  M.  E.,  Author  of 
"  The  Complete  Practical  Machinist,"  "  The  Pattern-maker's  Assist- 
ant," "  The  Slide-valve."  Illustrated  by  330  engravings.  8vo.,  313 
pages  $4.00 

ROSE.— The  Slide-Valve  Practically  Explained  :  « 
Embracing  simple  and  complete  Practical  Demonstrations  of  the 
operation  of  each  element  in  a  Slide-valve  Movement,  and  illustrating 
the  effects  of  Variations  in  their  Proportions  by  examples  carefully 
selected  from  the  most  recent  and  successful  practice.  By  Joshua 
Rose,  M.  E.,  Author  of  "  The  Complete  Practical  Machinist,"  "  The 
Pattern-maker's  Assistant,"  etc.    Illustrated  by  35  engravings  ^i.oo 

ROSELEUR. — Galvanoplastic  Manipulations  : 

A  Practical  Guide  for  the  Gold  and  Silver  Electroplater,  and  the 
Galvanoplastic  Operator.  By  Alfred  Roseleur,  Chemist,  Professor 
of  the  Galvanoplastic  Art,  Gold  and  Silver  Electroplater.  Edited 
from  the  fourth  French  edition,  with  the  addition  of  much  new  and 
original  American  matter,  bringing  it  up  to  the  best  practice  of  the 
present  day.  By  William  H.  Wahl,  Ph.  D.,  Secretary  of  the 
Franklin  Institute.    Illustrated  by  about  200  engravings.   (/«  press.) 

SHAW.— Civil  Architecture  : 

Being  a  Complete  Theoretical  and  Practical  System  of  Building,  con- 
taining the  Fundamental  Principles  of  the  Art.  By  Edward  Shaw, 
Architect.  To  which  is  added  a  Treatise  on  Gothic  Architecture,  etc. 
By  Thomas  W.  Silloway  and  George  M.  Harding,  Architects. 
The  whole  illustrated  by  102  quarto  plates  finely  engraved  on  copper. 
Eleventh  edition.    4to.      .......  $10.00 

SHUNK. — A  Practical  Treatise  on  Railway  Curves  and  Loca- 
tion, for  Young  Engineers. 
By  William  F.  SHtJNK,  Civil  Engineer.  ^i2mo.   Full  bound  pocket- 
book  form        .        .        .        .        .        .        .       .        .  $2.00 

SLATER.— The  Manual  of  Colors  and  Dye  Wares. 

By  J.  W.  Slater.    i2mo  $3-75 

SLOAN. — American  Houses: 

A  variety  of  Original  Designs  for  Rural  Buildings.  Illustrated  by 
twenty-six  colored  Engravings,  with  Descriptive  References.  By 
Samuel  Sloan,  Architect,  author  of  the  "  Model  Architect,"  etc., 
etc.    8vo.  $1.50 

SLOAN. — Homestead  Architecture : 

Containing  Forty  Designs  for  Villas,  Cottages,  and  Farm-houses,  with 
E'^says  on  Style,  Construction,  Landscape  Gardening,  Furniture,  etc., 
etc.  Illustrated  by  upwards  of  200  engravings.  By  Samuel  Sloan, 
Architect.    8vo  $3.50 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.  25 


SMEATON.— Builder's  Pocket-Companion : 

Containing  the  Elements  of  Building,  Surveying,  and  Architecture  ; 
with  Practical  Rules  and  Instructions  connected  with  the  subject.  By 
A.  C.  Smeaton,  Civil  Engineer,  etc.    i2mo.     .       .       .  $1.50 

SMITH. — A  Manual  of  Political  Economy. 

By  E.  Peshine  Smith.  A  new  Edition,  to  which  is  added  a  full 
Index.     l2mo.  ........  ^1-25 

SMITH  — Parks  and  Pleasure-Grounds  : 

Or  Practical  Notes  on  Country  Residences,  Villas,  Public  Parks,  and 
Gardens.  By  Charles  H.  J.  Smith,  Landscape  Gardener  and 
Garden  Architect,  etc.,  etc.    i2mo.  ....  ^2.00 

SMITH.— The  Dyer's  Instructor: 

Comprising  Practical  Instructions  in  the  Art  of  Dyeing  Silk,  Cotton, 
Wool,  and  Worsted,  and  Woolen  Goods ;  containing  nearly  800 
Receipts.  To  which  is  added  a  Treatise  on  the  Art  of  Padding;  and 
the  Printing  of  Silk  Warps,  Skeins,  and  Handkerchiefs,  and  the 
various  Mordants  and  Colors  for  the  different  styles  of  such  work. 
By  David  Smith,  Pattern  Dyer.    i2mo.  .       .       .  ^3.00 

SMYTH. — A  Rudimentary  Treatise  on  Coal  and  Coal-Mining. 
By  Warrington  W.  Smyth,  M.  A.,  F.  R.  G.,  President  R.  G.  S. 
of  Cornwall.    Fifth  edition,  revised  and  corrected.    With  numer- 
ous illustrations.    i2mo.  .       .       .        .        .        .  $^-7$ 

SNIVELY. — A  Treatise  on  the  Manufacture  of  Perfumes  and 
Kindred  Toilet  Articles. 
By  John  H.  Snively,  Phr.  D.,  Professor  of  Analytical  Chemistry  in 
the  Tennessee  College  of  Pharmacy.    8vo.       .        .        .  ^3.00 

SNIVELY.— Tables  for  Systematic  Qualitative  Chemical  Anal- 
ysis. 

By  John  H.  Snively,  Phr.  D.    8vo  ^i.oo 

SNIVELY.— The  Elements  of  Systematic  Qualitative  Chemical 
Analysis  : 

A  Hand-book  for  Beginners.  By  John  H.  Snively,  Phr.  D.  i6mo. 

^2.00 

STEWART.— The  American  System  : 

Speeches  on  the  Tariff  Question,  and  on  Internal  Improvements, 
principally  delivered  in  the  House  of  Representatives  of  the  United 
States.  By  Andrew  Stewart,  late  M.  C.  from  Pennsylvania. 
With  a  Portrait,  and  a  Biographical  Sketch.  8vo.  .  .  ^3.00 
STOKES.— The  Cabinet-Maker  and  Upholsterer's  Companion  : 
Comprising  the  Art  of  Drawing,  as  applicable  to  Cabinet  Work; 
Veneering,  Inlaying,  and  Buhl- Work ;  the  Art  of  Dyeing  and  Stain- 
ing Wood,  Ivory,  Bone,  Tortoise-Shell,  etc.  Directions  for  Lacker- 
ing, Japanning,  and  Varnishing;  to  make  French  Polish,  Glues. 
Cements,  and  Compositions;  with  numerous  Receipts,  useful  to  work- 
men generally.  By  J,  Stokes.  Illustrated.  A  New  Edition,  with 
an  Appendix  upon  French  Polishing,  Staining,  Imitating,  Varnishing, 
etc.,  etc.   i2mo  ^1.25 


26        HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


STRENGTH  AND  OTHER  PROPERTIES  OF  METALS: 

Reports  of  Experiments  on  the  Strength  and  other  Properties  of 
Metals  for  Cannon.  With  a  Description  of  the  Machines  for  Testing 
Metals,  and  of  the  Classification  of  Cannon  in  service.  By  Officers 
of  the  Ordnance  Department,  U.  S.  Army.  By  authority  of  the  Secre- 
tary of  War.    Illustrated  by  25  large  steel  plates.  Quarto  .  ^10.00 

SULLIVAN.— Protection  to  Native  Industry. 

By  Sir  Edward  Sullivan,  Baronet,  author  of  "  Ten  Chapters  on 
Social  Reforms."    8vo.    .......  $1.50 

SYME. — Outlines  of  an  Industrial  Science. 

By  David  Syme.    i2mo.         .       .       .       .       .       .  $2.00 

TABLES    SHOWING    THE    WEIGHT    OF  ROUND, 
SQUARE,  AND  FLAT  BAR  IRON,  STEEL,  ETC., 
By  Measurement.    Cloth  ......  63 

TAYLOR.— Statistics  of  Coal : 

Including  Mineral  Bituminous  Substances  employed  in  Arts  and 
Manufactures;  with  their  Geographical,  Geological,  and  Commercial 
Distribution  and  Amount  of  Production  and  Consumption  on  the 
American  Continent.  With  Incidental  Statistics  of  the  Iron  Manu- 
facture. By  R.  C.  Taylor.  Second  edition,  revised  by  S.  S.  Halde- 
man.  Illustrated  by  five  Maps  and  many  wood  engravings.  8vo., 
cloth  ^lO.OD 

TEMPLETON.— The  Practical  Examinator  on  Steam  and  the 
Steam-Engine : 

With  Instructive  References  relative  thereto,  arranged  for  the  Use  of 
Engineers,  Students,  and  others.  By  William  Templeton,  En- 
gineer.   i2mo.        ........  ^1.25 

THAUSING.— The  Theory  and  Practice  of  the  Preparation  of 
Malt  and  the  Fabrication  of  Beer: 
With  especial  reference  to  the  Vienna  Process  of  Brewing.  Elab- 
orated from  personal  experience  by  JULIUS  E.  Thausing,  Professor 
at  the  School  for  Brewers,  and  at  the  Agricultural  Institute,  Modling, 
near  Vienna.  Translated  from  the  German  by  William  T.  Brannt, 
Graduate  of  the  Royal  Agricultural  College  of  Eldena,  Prussia. 
Thoroughly  and  elaborately  edited,  with  much  American  matter,  and 
according  to  the  latest  and  most  Scientific  Practice,  by  A.  SCHWARZ, 
Graduate  of  the  Polytechnic  School  in  Prague,  Director  of  the  First 
Scientific  Station  for  Brewing  in  the  United  States,  Publisher  of 
"  The  American  Brewer,"  and  Dr.  A.  H.  Bauer,  M.  A.  C.  S.,  An- 
alytical Chemist,  and  Superintendent  of  the  above  Station,  Editor  of 
^'  The  American  Brewer."  Illustrated  by  140  engravings.  8vo. 
815  pages         .........  ^10.00 

THOMAS.— The  Modern  Practice  of  Photography. 

By  R.  W.  Thomas,  F.  C.  S.    8vo.  ....  75 

THOMPSON.— Political  Economy.    With  Especial  Reference 
to  the  Industrial  History  of  Nations. 
By  Robert  E.  Thompson,  M.  A.,  Professor  of  Social  Science  in  the 
University  of  Pennsylvania.    i2mo.         ....  ^1.50 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


27 


TURNER'S  (THE)  COMPANION: 

Containing  Instructions  in  Concentric,  Elliptic,  and  Eccentric  Turn- 
ing ;  also  various  Plates  of  Chucks,  Tools,  and  Instruments ;  and 
Directions  for  using  the  Eccentric  Cutter,  Drill,  Vertical  Cutter,  and 
Circular  Rest;  with  Patterns  and  Instructions  for  working  them. 
i2mo  ,  '     «  ^1-25 

TURNING  :  Specimens  of  Fancy  Turning  Executed  on  the 
Hand  or  Foot-Lathe  : 
With  Geometric,  Oval,  and  Eccentric  Chucks,  and  Elliptical  Cutting 
Frame.    By  an  Amateur.    Illustrated  by  30  exquisite  Photographs. 
4to.  ..........  ^3.00 

URBIN— BRULL.— A  Practical  Guide  for  Puddling  Iron  and 
Steel. 

By  Ed.  Urbin,  Engineer  of  Arts  and  Manufactures.  A  Prize  Essay, 
read  before  the  Association  of  Engineers,  Graduate  of  the  School  of 
Mines,  of  Liege,  Belgium,  at  the  Meeting  of  1865-6.  To  which  is 
added  A  Comparison  of  the  Resisting  Properties  of  Iron  and 
Steel.  By  A.  Brull.  Translated  from  the  French  by  A.  A.  Fes- 
quet,  Chemist  and  Engineer.  8vo.  ....  ^i.oo 
VAILE. — Galvanized-Iron  Cornice-Worker's  Manual: 

Containing  Instructions  in  Laying  out  the  Different  Mitres,  and 
Making  Patterns  for  all  kinds  of  Plain  and  Circular  Work.  Also, 
Tables  of  Weights,  Areas  and  Circumferences  of  Circles,  and  olher 
Matter  calculated  to  Benefit  the  Trade.  By  Charles  A.  Vaile. 
Illustrated  by  twenty-one  plates.   4to  ^5-00 

VILLE. — On  Artificial  Manures  : 

Their  Chemical  Selection  and  Scientific  Application  to  Agriculture. 
A  series  of  Lectures  given  at  the  Experimental  Farm  at  Vincennes, 
during  1867  and  1874-75.  By  M.  Georges  Ville.  Translated  and 
Edited  by  WiLLlAM  Crookes,  F.  R.  S.  Illustrated  by  thirty-one 
engravings.   8vo.,  450  pages  ^6.00 

VILLE.— The  School  of  Chemical  Manures  : 

Or,  Elementary  Principles  in  the  Use  of  Fertilizing  Agents.  From 
the  French  of  M.  Geo.  Ville,  by  A.  A.  Fesqukt,  Chemist  and  En- 
.gineer.    With  Illustrations.    i2mo.  ....  ^1.25 

VOGDES. — The  Architect's  and  Builder's  Pocket- Companion 
and  Price-Book : 
Consisting  of  a  Short  but  Comprehensive  Epitome  of  Decimals,  Duo- 
decimals, Geometry,  and  Mensuration ;  with  Tables  of  U.  S.  Meas- 
ures, Sizes,  Weights,  Strengths,  etc.,  of  Iron,  Wood,  Stone,  and 
various  other  Materials,  Quantities  of  Materials  in  Given  Sizes,  and 
Dimensions  of  Wood,  Brick,  and  Stone;  and  a  full  and  complete 
Bill  of  Prices  for  Carpenter's  Work;  also.  Rules  for  Computing  and 
Valuing  Brick  and  Brick  Work,  Stone  Work,  Paii  ting,  Plastering, 

■  etc.    By  Frank  W.  Vogdes,  Architect.    Illustrated.    Full  bound 

in  pocket-book  form  j^2.oo 

Bound  in  cloth  1.50 


28       HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


WARE.— The  Sugar  Beet. 

Including  a  History  of  the  Beet  Sugar  Industry  in  Europe,  Varieties 
of  the  Sugar  Beet,  Examination,  Soils,  Tillage,  Seeds  and  Sowing, 
Yield  and  Cost  of  Cultivation,  Harvesting,  Transportation,  Conserva- 
tion, Feeding  Qualities  of  the  Beet  and  of  the  Pulp,  etc.  By  Lewis 
S.  Ware,  C.  E.,  M.  E.    Illustrated  by  ninety  engravings.  8vo. 

^4.00 

WARN.— The  Sheet-Metal  Worker's  Instructor: 

P'or  Zinc,  SheetTron,  Copper,  and  Tin-Piate  Workers,  etc.  Contain- 
ing a  selection  of  Geometrical  Problems ;  also.  Practical  and  Simple 
Rules  for  Describing  the  various  Patterns  required  in  the  different 
branches  of  the  above  Trades.  By  Reuben  H.  Warn,  Practical 
Tin-Plate  Worker,  To  which  is  added  an  Appendix,  containing 
Instructions  for  Boiler-Making,  Mensuration  of  Surfaces  and  Solids, 
Rules  for  Calculating  the  Weights  of  different  Figures  of  Iron  and 
Steel,  Tables  of  the  Weights  of  Iron,  Steel,  etc.  Illustrated  by  thirty- 
two  Plates  and  thirty-seven  Wood  Engravings.    Svo.        .  ^3.00 

WARNER.— New  Theorems,  Tables,  and  Diagrams,  for  the 
Computation  of  Earth-work : 

Designed  for  the  use  of  Engineers  in  Preliminary  and  Final  Estimates, 
of  Students  in  Engineering,  and  of  Contractors  and  other  non-profes- 
sional Computers.  In  two  parts,  with  an  Appendix.  Part  I.  A  Prac- 
tical Treatise;  Part  II.  A  Theoretical  Treatise,  and  the  Appendix. 
Containing  Notes  to  the  Rules  and  Examples  of  Part  I. ;  Explana- 
tions of  the  Construction  of  Scales,  Tables,  and  Diagrams,  and  a 
Treatise  upon  Equivalent  Square  Bases  and  Equivalent  Level  Heights. 
The  whole  illustrated  by  numerous  original  engravings,  comprising 
explanatory  cuts  for  Definitions  and  Problems,  Stereometric  Scales 
and  Diagrams,  and  a  series  of  Lithographic  Drawings  from  Models  : 
Showing  all  the  Combinations  of  Solid  Forms  which  occur  in  Railroad 
Excavations  and  Embankments.  By  JoHN  Warner,  A.  M.,  Mining 
and  Mechanical  Engineer.  Illustrated  by  14  Plates.  A  new,  revised 
and  improved  edition.    Svo.     ......  ^4,00 

WATSON.— A  Manual  of  the  Hand-Lathe  : 

Comprising  Concise  Directions  for  Working  Metals  of  all  kinds. 
Ivory,  Bone  and  Precious  Woods;  Dyeing,  Coloring,  and  French 
Polishing;  Inlaying  by  Veneers,  and  various  methods  practised  to 
produce  Elaborate  work  with  Dispatch,  and  at  Small  Expense.  By 
Egbert  P.  Watson,  Author  of  "  The  Modern  Practice  of  American 
Machinists  and  Engineers."    Illustrated  by  78  engravings.  ^1.50 

lA^ATSON. — The  Modern  Practice  of  American  Machinists  and 
Engineers  : 

Including  the  Construction,  Application,  and  Use  of  Drills,  Lathe 
Tools,  Cutters  for  Boring  Cylinders,  and  Hollow-work  generally,  with 
the  most  Economical  Speed  for  the  same  ;  the  Results  verified  by 
Actual  Practice  at  the  Lathe,  the  Vise,  and  on  the  Floor.  Together 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.  29 


with  Workshop  Management,  Economy  of  Manufacture,  the  Steam- 
Engine,  Boilers,  Gears,  Behing,  etc.,  etc.  By  Egbert  P.  Watson. 
Illustrated  by  eighty-six  engravings.    l2mo.       .        .        .  ^2.50 

WATSON.— The  Theory  and  Practice  of  the  Art  of  Weaving 
by  Hand  and  Power  : 
With  Calculations  and  Tables  for  the  Use  of  those  connected  with  the 
Trade.  By  John  Watson,  Manufacturer  and  Practical  Machine- 
Maker.  Illustrated  by  large  Drawings  of  the  best  Power  Looms. 
8vo,         .       .        .        •  •$7-50 

WEATHERLY.— Treatise  on  the  Art  of  Boiling  Sugar,  Crys- 
tallizing, Lozenge-making,  Comfits,  Gum  Goods, 
And  other  processes  for  Confectionery,  etc.,  in  which  are  explained, 
in  an  easy  and  familiar  manner,  the  various  Methods  of  Manufactur- 
ing every  Description  of  Raw  and  Refined  Sugar  Goods,  as  sold  by 
Confectioners  and  others.    i2mo.      .....  ^1.50 

WEDDING.— Elements  of  the  Metallurgy  of  Iron. 

By  Dr.  Hermann  Wedding,  Royal  Privy  Counsellor  of  Mines,  Ber- 
lin, Prussia.  Translated  from  the  second  revised  and  rewritten  Ger- 
man edition.  By  William  T.  Brannt,  Graduate  of  the  Royal  Ag- 
ricultural College  at  Eldena,  Prussia.  Edited  by  William  H. 
Wahl,  Ph.D.,  Secretary  of  the  Franklin  Institute,  Philadelphia, 
Illustrated  by  about  250  engravings.  8vo.,  about  500  pages  {In  prep- 
aration.') ......... 

WEINHOLD.— Introduction  to  Experimental  Physics,  Theo- 
retical and  Practical. 
Including  directions  for  Constructing  Physical  Apparatus  and  for 
Making  Experiments.  By  Adolf  F.  Weinhold,  Professor  in  the 
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